diff --git a/src/sfizz/FilePool.cpp b/src/sfizz/FilePool.cpp
index d5471a12..3cd57684 100644
--- a/src/sfizz/FilePool.cpp
+++ b/src/sfizz/FilePool.cpp
@@ -90,6 +90,10 @@ void streamFromFile(SndfileHandle& sndFile, uint32_t numFrames, sfz::Oversamplin
 sfz::FilePool::FilePool(sfz::Logger& logger)
 : logger(logger)
 {
+    FilePromise promise;
+    if (!promise.dataStatus.is_lock_free())
+        DBG("atomic<DataStatus> is not lock-free; could cause issues with locking");
+
     for (int i = 0; i < config::numBackgroundThreads; ++i)
         threadPool.emplace_back( &FilePool::loadingThread, this );
 
@@ -166,13 +170,16 @@ bool sfz::FilePool::checkSample(std::string& filename) const noexcept
 #endif
 }
 
-absl::optional<sfz::FilePool::FileInformation> sfz::FilePool::getFileInformation(const std::string& filename) noexcept
+absl::optional<sfz::FileInformation> sfz::FilePool::getFileInformation(const std::string& filename) noexcept
 {
     fs::path file { rootDirectory / filename };
 
+    if (!fs::exists(file))
+        return {};
+
     SndfileHandle sndFile(file.string().c_str());
     if (sndFile.channels() != 1 && sndFile.channels() != 2) {
-        DBG("Missing logic for " << sndFile.channels() << " channels, discarding sample " << filename);
+        DBG("[sfizz] Missing logic for " << sndFile.channels() << " channels, discarding sample " << filename);
         return {};
     }
 
@@ -194,13 +201,11 @@ absl::optional<sfz::FilePool::FileInformation> sfz::FilePool::getFileInformation
 bool sfz::FilePool::preloadFile(const std::string& filename, uint32_t maxOffset) noexcept
 {
     fs::path file { rootDirectory / filename };
-
-    if (!fs::exists(file))
+    auto fileInformation = getFileInformation(filename);
+    if (!fileInformation)
         return false;
 
     SndfileHandle sndFile(file.string().c_str());
-    if (sndFile.channels() != 1 && sndFile.channels() != 2)
-        return false;
 
     // FIXME: Large offsets will require large preloading; is this OK in practice? Apparently sforzando does the same
     const auto frames = static_cast<uint32_t>(sndFile.frames());
@@ -211,19 +216,47 @@ bool sfz::FilePool::preloadFile(const std::string& filename, uint32_t maxOffset)
             return min(frames, maxOffset + preloadSize);
     }();
 
-    if (preloadedFiles.contains(filename)) {
-        if (framesToLoad > preloadedFiles[filename].preloadedData->getNumFrames()) {
+    const auto existingFile = preloadedFiles.find(filename);
+    if (existingFile != preloadedFiles.end()) {
+        if (framesToLoad > existingFile->second.preloadedData->getNumFrames()) {
             preloadedFiles[filename].preloadedData = readFromFile<float>(sndFile, framesToLoad, oversamplingFactor);
         }
     } else {
-        const float sourceSampleRate { static_cast<float>(oversamplingFactor) * static_cast<float>(sndFile.samplerate()) };
-        PreloadedFileHandle handle { readFromFile<float>(sndFile, framesToLoad, oversamplingFactor), sourceSampleRate };
+        fileInformation->sampleRate = static_cast<float>(oversamplingFactor) * static_cast<float>(sndFile.samplerate());
+        FileDataHandle handle {
+            readFromFile<float>(sndFile, framesToLoad, oversamplingFactor),
+            *fileInformation
+        };
         preloadedFiles.insert_or_assign(filename, handle);
     }
-
     return true;
 }
 
+absl::optional<sfz::FileDataHandle> sfz::FilePool::loadFile(const std::string& filename) noexcept
+{
+    fs::path file { rootDirectory / filename };
+    auto fileInformation = getFileInformation(filename);
+    if (!fileInformation)
+        return {};
+
+    SndfileHandle sndFile(file.string().c_str());
+
+    // FIXME: Large offsets will require large preloading; is this OK in practice? Apparently sforzando does the same
+    const auto frames = static_cast<uint32_t>(sndFile.frames());
+    const auto existingFile = loadedFiles.find(filename);
+    if (existingFile != loadedFiles.end()) {
+        return existingFile->second;
+    } else {
+        fileInformation->sampleRate = static_cast<float>(oversamplingFactor) * static_cast<float>(sndFile.samplerate());
+        FileDataHandle handle {
+            readFromFile<float>(sndFile, frames, oversamplingFactor),
+            *fileInformation
+        };
+        loadedFiles.insert_or_assign(filename, handle);
+        return handle;
+    }
+}
+
 sfz::FilePromisePtr sfz::FilePool::getFilePromise(const std::string& filename) noexcept
 {
     if (emptyPromises.empty()) {
@@ -240,7 +273,7 @@ sfz::FilePromisePtr sfz::FilePool::getFilePromise(const std::string& filename) n
     auto promise = emptyPromises.back();
     promise->filename = preloaded->first;
     promise->preloadedData = preloaded->second.preloadedData;
-    promise->sampleRate = preloaded->second.sampleRate;
+    promise->sampleRate = preloaded->second.information.sampleRate;
     promise->oversamplingFactor = oversamplingFactor;
     promise->creationTime = std::chrono::high_resolution_clock::now();
 
@@ -274,7 +307,7 @@ void sfz::FilePool::tryToClearPromises()
         std::this_thread::sleep_for(std::chrono::milliseconds(1));
 
     for (auto& promise: promisesToClear) {
-        if (promise->dataReady)
+        if (promise->dataStatus != FilePromise::DataStatus::Wait)
             promise->reset();
     }
 }
@@ -313,11 +346,12 @@ void sfz::FilePool::loadingThread() noexcept
         SndfileHandle sndFile(file.string().c_str());
         if (sndFile.error() != 0) {
             DBG("[sfizz] libsndfile errored for " << promise->filename << " with message " << sndFile.strError());
+            promise->dataStatus = FilePromise::DataStatus::Error;
             continue;
         }
         const auto frames = static_cast<uint32_t>(sndFile.frames());
         streamFromFile<float>(sndFile, frames, oversamplingFactor, promise->fileData, &promise->availableFrames);
-        promise->dataReady = true;
+        promise->dataStatus = FilePromise::DataStatus::Ready;
         const auto loadDuration = std::chrono::high_resolution_clock::now() - loadStartTime;
         logger.logFileTime(waitDuration, loadDuration, frames, promise->filename);
 
@@ -352,7 +386,7 @@ void sfz::FilePool::cleanupPromises() noexcept
     auto clearedIterator = promisesToClear.begin();
     auto clearedSentinel = promisesToClear.rbegin();
     while (clearedIterator < clearedSentinel.base()) {
-        if (clearedIterator->get()->dataReady == false) {
+        if (clearedIterator->get()->dataStatus == FilePromise::DataStatus::Wait) {
             emptyPromises.push_back(*clearedIterator);
             std::iter_swap(clearedIterator, clearedSentinel);
             ++clearedSentinel;
@@ -391,7 +425,7 @@ void sfz::FilePool::setOversamplingFactor(sfz::Oversampling factor) noexcept
         fs::path file { rootDirectory / std::string(preloadedFile.first) };
         SndfileHandle sndFile(file.string().c_str());
         preloadedFile.second.preloadedData = readFromFile<float>(sndFile, preloadSize + maxOffset, factor);
-        preloadedFile.second.sampleRate *= samplerateChange;
+        preloadedFile.second.information.sampleRate *= samplerateChange;
     }
 
     this->oversamplingFactor = factor;
diff --git a/src/sfizz/FilePool.h b/src/sfizz/FilePool.h
index c75e6c75..450a4c24 100644
--- a/src/sfizz/FilePool.h
+++ b/src/sfizz/FilePool.h
@@ -38,24 +38,31 @@
 #include "Logger.h"
 #include <chrono>
 #include <thread>
-#include <sndfile.hh>
 
 namespace sfz {
 using AudioBufferPtr = std::shared_ptr<AudioBuffer<float>>;
 
 
+struct FileInformation {
+    uint32_t end { Default::sampleEndRange.getEnd() };
+    uint32_t loopBegin { Default::loopRange.getStart() };
+    uint32_t loopEnd { Default::loopRange.getEnd() };
+    double sampleRate { config::defaultSampleRate };
+    int numChannels { 0 };
+};
+
 // Strict C++11 disallows member initialization if aggregate initialization is to be used...
-struct PreloadedFileHandle
+struct FileDataHandle
 {
     std::shared_ptr<AudioBuffer<float>> preloadedData;
-    float sampleRate;
+    FileInformation information;
 };
 
 struct FilePromise
 {
     AudioSpan<const float> getData()
     {
-        if (dataReady)
+        if (dataStatus == DataStatus::Ready)
             return AudioSpan<const float>(fileData);
         else if (availableFrames > preloadedData->getNumFrames())
             return AudioSpan<const float>(fileData).first(availableFrames);
@@ -69,18 +76,30 @@ struct FilePromise
         preloadedData.reset();
         filename = "";
         availableFrames = 0;
-        dataReady = false;
+        dataStatus = DataStatus::Wait;
         oversamplingFactor = config::defaultOversamplingFactor;
         sampleRate = config::defaultSampleRate;
     }
 
+    void waitCompletion()
+    {
+        while (dataStatus == DataStatus::Wait)
+            std::this_thread::sleep_for(std::chrono::milliseconds(50));
+    }
+
+    enum class DataStatus {
+        Wait = 0,
+        Ready,
+        Error,
+    };
+
     absl::string_view filename {};
     AudioBufferPtr preloadedData {};
     AudioBuffer<float> fileData {};
     float sampleRate { config::defaultSampleRate };
     Oversampling oversamplingFactor { config::defaultOversamplingFactor };
     std::atomic<size_t> availableFrames { 0 };
-    std::atomic<bool> dataReady { false };
+    std::atomic<DataStatus> dataStatus { DataStatus::Wait };
     std::chrono::time_point<std::chrono::high_resolution_clock> creationTime;
 
     LEAK_DETECTOR(FilePromise);
@@ -131,14 +150,6 @@ public:
      */
     size_t getNumPreloadedSamples() const noexcept { return preloadedFiles.size(); }
 
-    struct FileInformation {
-        uint32_t end { Default::sampleEndRange.getEnd() };
-        uint32_t loopBegin { Default::loopRange.getStart() };
-        uint32_t loopEnd { Default::loopRange.getEnd() };
-        double sampleRate { config::defaultSampleRate };
-        int numChannels { 0 };
-    };
-
     /**
      * @brief Get metadata information about a file.
      *
@@ -148,7 +159,7 @@ public:
     absl::optional<FileInformation> getFileInformation(const std::string& filename) noexcept;
 
     /**
-     * @brief Check that a file is preloaded with the proper offset bounds
+     * @brief Preload a file with the proper offset bounds
      *
      * @param filename
      * @param offset the maximum offset to consider for preloading. The total preloaded
@@ -158,6 +169,15 @@ public:
      */
     bool preloadFile(const std::string& filename, uint32_t maxOffset) noexcept;
 
+    /**
+     * @brief Load a file and return its information. The file pool will store this
+     * data for future requests so use this function responsibly.
+     *
+     * @param filename
+     * @return A handle on the file data
+     */
+    absl::optional<sfz::FileDataHandle> loadFile(const std::string& filename) noexcept;
+
     /**
      * @brief Check that the sample exists. If not, try to find it in a case insensitive way.
      *
@@ -247,7 +267,9 @@ private:
     std::atomic<bool> addingPromisesToClear { false };
     std::atomic<bool> canAddPromisesToClear { true };
 
-    absl::flat_hash_map<absl::string_view, PreloadedFileHandle> preloadedFiles;
+    // Preloaded data
+    absl::flat_hash_map<absl::string_view, FileDataHandle> preloadedFiles;
+    absl::flat_hash_map<absl::string_view, FileDataHandle> loadedFiles;
     std::vector<std::thread> threadPool { };
     LEAK_DETECTOR(FilePool);
 };
diff --git a/src/sfizz/Region.cpp b/src/sfizz/Region.cpp
index 8d8f14ee..808f031e 100644
--- a/src/sfizz/Region.cpp
+++ b/src/sfizz/Region.cpp
@@ -52,14 +52,12 @@ bool sfz::Region::parseOpcode(const Opcode& opcode)
         break;
     case hash("delay_random"):
         setValueFromOpcode(opcode, delayRandom, Default::delayRange);
-        delayDistribution.param(std::uniform_real_distribution<float>::param_type(0, delayRandom));
         break;
     case hash("offset"):
         setValueFromOpcode(opcode, offset, Default::offsetRange);
         break;
     case hash("offset_random"):
         setValueFromOpcode(opcode, offsetRandom, Default::offsetRange);
-        offsetDistribution.param(std::uniform_int_distribution<uint32_t>::param_type(0, offsetRandom));
         break;
     case hash("end"):
         setValueFromOpcode(opcode, sampleEnd, Default::sampleEndRange);
@@ -99,6 +97,10 @@ bool sfz::Region::parseOpcode(const Opcode& opcode)
     case hash("oscillator_phase"):
         setValueFromOpcode(opcode, oscillatorPhase, Default::oscillatorPhaseRange);
         break;
+    case hash("oscillator"):
+        if (auto value = readBooleanFromOpcode(opcode))
+            oscillator = *value;
+        break;
 
     // Instrument settings: voice lifecycle
     case hash("group"): // fallthrough
@@ -297,7 +299,6 @@ bool sfz::Region::parseOpcode(const Opcode& opcode)
         break;
     case hash("amp_random"):
         setValueFromOpcode(opcode, ampRandom, Default::ampRandomRange);
-        volumeDistribution.param(std::uniform_real_distribution<float>::param_type(0, ampRandom));
         break;
     case hash("amp_velcurve_&"):
         {
@@ -639,7 +640,6 @@ bool sfz::Region::parseOpcode(const Opcode& opcode)
         break;
     case hash("pitch_random"):
         setValueFromOpcode(opcode, pitchRandom, Default::pitchRandomRange);
-        pitchDistribution.param(std::uniform_int_distribution<int>::param_type(-pitchRandom, pitchRandom));
         break;
     case hash("transpose"):
         setValueFromOpcode(opcode, transpose, Default::transposeRange);
@@ -891,8 +891,9 @@ void sfz::Region::registerTempo(float secondsPerQuarter) noexcept
         bpmSwitched = false;
 }
 
-float sfz::Region::getBasePitchVariation(int noteNumber, uint8_t velocity) noexcept
+float sfz::Region::getBasePitchVariation(int noteNumber, uint8_t velocity) const noexcept
 {
+    std::uniform_int_distribution<int> pitchDistribution { -pitchRandom, pitchRandom };
     auto pitchVariationInCents = pitchKeytrack * (noteNumber - (int)pitchKeycenter); // note difference with pitch center
     pitchVariationInCents += tune; // sample tuning
     pitchVariationInCents += config::centPerSemitone * transpose; // sample transpose
@@ -901,26 +902,42 @@ float sfz::Region::getBasePitchVariation(int noteNumber, uint8_t velocity) noexc
     return centsFactor(pitchVariationInCents);
 }
 
-float sfz::Region::getBaseVolumedB(int noteNumber) noexcept
+float sfz::Region::getBaseVolumedB(int noteNumber) const noexcept
 {
+    std::uniform_real_distribution<float> volumeDistribution { -ampRandom, ampRandom };
     auto baseVolumedB = volume + volumeDistribution(Random::randomGenerator);
     if (trigger == SfzTrigger::release || trigger == SfzTrigger::release_key)
         baseVolumedB -= rtDecay * midiState.getNoteDuration(noteNumber);
     return baseVolumedB;
 }
 
-float sfz::Region::getBaseGain() noexcept
+float sfz::Region::getBaseGain() const noexcept
 {
     return normalizePercents(amplitude);
 }
 
-uint32_t sfz::Region::getOffset(Oversampling factor) noexcept
+float sfz::Region::getPhase() const noexcept
 {
+    float phase;
+    if (oscillatorPhase >= 0) {
+        phase = oscillatorPhase * (1.0f / 360.0f);
+        phase -= static_cast<int>(phase);
+    } else {
+        std::uniform_real_distribution<float> phaseDist { 0.0001f, 0.9999f };
+        phase = phaseDist(Random::randomGenerator);
+    }
+    return phase;
+}
+
+uint32_t sfz::Region::getOffset(Oversampling factor) const noexcept
+{
+    std::uniform_int_distribution<uint32_t> offsetDistribution { 0, offsetRandom };
     return (offset + offsetDistribution(Random::randomGenerator)) * static_cast<uint32_t>(factor);
 }
 
-float sfz::Region::getDelay() noexcept
+float sfz::Region::getDelay() const noexcept
 {
+    std::uniform_real_distribution<float> delayDistribution { 0, delayRandom };
     return delay + delayDistribution(Random::randomGenerator);
 }
 
@@ -971,7 +988,7 @@ float crossfadeOut(const sfz::Range<T>& crossfadeRange, U value, SfzCrossfadeCur
     return 1.0f;
 }
 
-float sfz::Region::getNoteGain(int noteNumber, uint8_t velocity) noexcept
+float sfz::Region::getNoteGain(int noteNumber, uint8_t velocity) const noexcept
 {
     float baseGain { 1.0f };
 
@@ -992,7 +1009,7 @@ float sfz::Region::getNoteGain(int noteNumber, uint8_t velocity) noexcept
     return baseGain;
 }
 
-float sfz::Region::getCrossfadeGain(const sfz::SfzCCArray& ccState) noexcept
+float sfz::Region::getCrossfadeGain(const sfz::SfzCCArray& ccState) const noexcept
 {
     float gain { 1.0f };
 
diff --git a/src/sfizz/Region.h b/src/sfizz/Region.h
index 3ef284d0..1fd0fa67 100644
--- a/src/sfizz/Region.h
+++ b/src/sfizz/Region.h
@@ -135,7 +135,7 @@ struct Region {
      * @param velocity
      * @return float
      */
-    float getBasePitchVariation(int noteNumber, uint8_t velocity) noexcept;
+    float getBasePitchVariation(int noteNumber, uint8_t velocity) const noexcept;
     /**
      * @brief Get the note-related gain of the region depending on which note has been
      * pressed and at which velocity.
@@ -144,7 +144,7 @@ struct Region {
      * @param velocity
      * @return float
      */
-    float getNoteGain(int noteNumber, uint8_t velocity) noexcept;
+    float getNoteGain(int noteNumber, uint8_t velocity) const noexcept;
     /**
      * @brief Get the additional crossfade gain of the region depending on the
      * CC values
@@ -152,7 +152,7 @@ struct Region {
      * @param ccState
      * @return float
      */
-    float getCrossfadeGain(const SfzCCArray& ccState) noexcept;
+    float getCrossfadeGain(const SfzCCArray& ccState) const noexcept;
     /**
      * @brief Get the base volume of the region depending on which note has been
      * pressed to trigger the region.
@@ -160,13 +160,19 @@ struct Region {
      * @param noteNumber
      * @return float
      */
-    float getBaseVolumedB(int noteNumber) noexcept;
+    float getBaseVolumedB(int noteNumber) const noexcept;
     /**
      * @brief Get the base gain of the region.
      *
      * @return float
      */
-    float getBaseGain() noexcept;
+    float getBaseGain() const noexcept;
+    /**
+     * @brief Get the base gain of the region.
+     *
+     * @return float
+     */
+    float getPhase() const noexcept;
     /**
      * @brief Computes the gain value related to the velocity of the note
      *
@@ -178,13 +184,13 @@ struct Region {
      *
      * @return uint32_t
      */
-    uint32_t getOffset(Oversampling factor = Oversampling::x1) noexcept;
+    uint32_t getOffset(Oversampling factor = Oversampling::x1) const noexcept;
     /**
      * @brief Get the region delay in seconds
      *
      * @return float
      */
-    float getDelay() noexcept;
+    float getDelay() const noexcept;
     /**
      * @brief Get the index of the sample end, either natural end or forced
      * loop.
@@ -228,6 +234,7 @@ struct Region {
 
     // Wavetable oscillator
     float oscillatorPhase { Default::oscillatorPhase };
+    bool oscillator = false;
 
     // Instrument settings: voice lifecycle
     uint32_t group { Default::group }; // group
@@ -326,11 +333,6 @@ private:
     absl::string_view defaultPath { "" };
 
     int sequenceCounter { 0 };
-
-    std::uniform_real_distribution<float> volumeDistribution { -sfz::Default::ampRandom, sfz::Default::ampRandom };
-    std::uniform_real_distribution<float> delayDistribution { 0, sfz::Default::delayRandom };
-    std::uniform_int_distribution<uint32_t> offsetDistribution { 0, sfz::Default::offsetRandom };
-    std::uniform_int_distribution<int> pitchDistribution { -sfz::Default::pitchRandom, sfz::Default::pitchRandom };
     LEAK_DETECTOR(Region);
 };
 
diff --git a/src/sfizz/Synth.cpp b/src/sfizz/Synth.cpp
index 930e1c9e..9ef64406 100644
--- a/src/sfizz/Synth.cpp
+++ b/src/sfizz/Synth.cpp
@@ -143,6 +143,7 @@ void sfz::Synth::clear()
     effectBuses[0]->setSampleRate(sampleRate);
     curves = CurveSet::createPredefined();
     resources.filePool.clear();
+    resources.wavePool.clearFileWaves();
     resources.logger.clear();
     numGroups = 0;
     numMasters = 0;
@@ -324,7 +325,7 @@ bool sfz::Synth::loadSfzFile(const fs::path& file)
     while (currentRegion < lastRegion.base()) {
         auto region = currentRegion->get();
 
-        if (!region->isGenerator()) {
+        if (!region->oscillator && !region->isGenerator()) {
             if (!resources.filePool.checkSample(region->sample)) {
                 removeCurrentRegion();
                 continue;
@@ -360,6 +361,17 @@ bool sfz::Synth::loadSfzFile(const fs::path& file)
             if (!resources.filePool.preloadFile(region->sample, maxOffset))
                 removeCurrentRegion();
         }
+        else if (region->oscillator && !region->isGenerator()) {
+            if (!resources.filePool.checkSample(region->sample)) {
+                removeCurrentRegion();
+                continue;
+            }
+
+            if (!resources.wavePool.createFileWave(resources.filePool, region->sample)) {
+                removeCurrentRegion();
+                continue;
+            }
+        }
 
         for (auto note = 0; note < 128; note++) {
             if (region->keyRange.containsWithEnd(note) ||
diff --git a/src/sfizz/Voice.cpp b/src/sfizz/Voice.cpp
index 743c00f7..e86375f2 100644
--- a/src/sfizz/Voice.cpp
+++ b/src/sfizz/Voice.cpp
@@ -58,17 +58,11 @@ void sfz::Voice::startVoice(Region* region, int delay, int number, uint8_t value
             break;
         }
         waveOscillator.setWavetable(wave);
-
-        float phase;
-        const float phaseParam = region->oscillatorPhase;
-        if (phaseParam >= 0) {
-            phase = phaseParam * (1.0f / 360.0f);
-            phase -= static_cast<int>(phase);
-        } else {
-            std::uniform_real_distribution<float> phaseDist { 0.0001f, 0.9999f };
-            phase = phaseDist(Random::randomGenerator);
-        }
-        waveOscillator.setPhase(phase);
+        waveOscillator.setPhase(region->getPhase());
+    } else if (region->oscillator) {
+        const WavetableMulti* wave = resources.wavePool.getFileWave(region->sample);
+        waveOscillator.setWavetable(wave);
+        waveOscillator.setPhase(region->getPhase());
     } else {
         currentPromise = resources.filePool.getFilePromise(region->sample);
         if (currentPromise == nullptr) {
@@ -77,6 +71,7 @@ void sfz::Voice::startVoice(Region* region, int delay, int number, uint8_t value
         }
         speedRatio = static_cast<float>(currentPromise->sampleRate / this->sampleRate);
     }
+
     pitchRatio = region->getBasePitchVariation(number, value);
 
     baseVolumedB = region->getBaseVolumedB(number);
@@ -294,7 +289,7 @@ void sfz::Voice::renderBlock(AudioSpan<float> buffer) noexcept
 
     { // Fill buffer with raw data
         ScopedTiming logger { dataDuration };
-        if (region->isGenerator())
+        if (region->isGenerator() || region->oscillator)
             fillWithGenerator(delayed_buffer);
         else
             fillWithData(delayed_buffer);
diff --git a/src/sfizz/Wavetables.cpp b/src/sfizz/Wavetables.cpp
index 355b9fca..c65b244a 100644
--- a/src/sfizz/Wavetables.cpp
+++ b/src/sfizz/Wavetables.cpp
@@ -5,18 +5,16 @@
 // If not, contact the sfizz maintainers at https://github.com/sfztools/sfizz
 
 #include "Wavetables.h"
+#include "FilePool.h"
 #include "MathHelpers.h"
 #include <kiss_fftr.h>
-#include <memory>
 
 namespace sfz {
 
-static WavetableMulti silenceMulti = WavetableMulti::createSilence();
-
 void WavetableOscillator::init(double sampleRate)
 {
     _sampleInterval = 1.0 / sampleRate;
-    _multi = &silenceMulti;
+    _multi = WavetableMulti::getSilenceWavetable();
     clear();
 }
 
@@ -27,7 +25,7 @@ void WavetableOscillator::clear()
 
 void WavetableOscillator::setWavetable(const WavetableMulti* wave)
 {
-    _multi = wave ? wave : &silenceMulti;
+    _multi = wave ? wave : WavetableMulti::getSilenceWavetable();
 }
 
 void WavetableOscillator::setPhase(float phase)
@@ -252,12 +250,12 @@ WavetableMulti WavetableMulti::createForHarmonicProfile(
     return wm;
 }
 
-WavetableMulti WavetableMulti::createSilence()
+const WavetableMulti* WavetableMulti::getSilenceWavetable()
 {
-    WavetableMulti wm;
+    static WavetableMulti wm;
     wm.allocateStorage(1);
     wm.fillExtra();
-    return wm;
+    return &wm;
 }
 
 void WavetableMulti::allocateStorage(unsigned tableSize)
@@ -279,6 +277,31 @@ void WavetableMulti::fillExtra()
     }
 }
 
+//------------------------------------------------------------------------------
+
+/**
+ * @brief Harmonic profile which takes its values from a table.
+ */
+class TabulatedHarmonicProfile : public HarmonicProfile {
+public:
+    explicit TabulatedHarmonicProfile(absl::Span<const std::complex<float>> harmonics)
+        : _harmonics(harmonics)
+    {
+    }
+
+    std::complex<double> getHarmonic(size_t index) const override
+    {
+        if (index >= _harmonics.size())
+            return {};
+
+        return _harmonics[index];
+    }
+
+private:
+    absl::Span<const std::complex<float>> _harmonics;
+};
+
+//------------------------------------------------------------------------------
 
 WavetablePool::WavetablePool()
 {
@@ -313,4 +336,60 @@ const WavetableMulti* WavetablePool::getWaveSquare()
     return &wave;
 }
 
+const WavetableMulti* WavetablePool::getFileWave(const std::string& filename)
+{
+    auto it = _fileWaves.find(filename);
+    if (it == _fileWaves.end())
+        return nullptr;
+
+    return it->second.get();
+}
+
+void WavetablePool::clearFileWaves()
+{
+    _fileWaves.clear();
+}
+
+bool WavetablePool::createFileWave(FilePool& filePool, const std::string& filename)
+{
+    if (_fileWaves.contains(filename))
+        return true;
+
+    auto fileHandle = filePool.loadFile(filename);
+    if (!fileHandle)
+        return false;
+
+    if (fileHandle->information.numChannels > 1)
+        DBG("[sfizz] Only the first channel of " << filename << " will be used to create the wavetable");
+
+    auto audioData = fileHandle->preloadedData->getConstSpan(0);
+    size_t fftSize = audioData.size();
+    size_t specSize = fftSize / 2 + 1;
+
+    typedef std::complex<kiss_fft_scalar> cpx;
+    std::unique_ptr<cpx[]> spec { new cpx[specSize] };
+
+    kiss_fftr_cfg cfg = kiss_fftr_alloc(fftSize, false, nullptr, nullptr);
+    if (!cfg)
+        throw std::bad_alloc();
+
+    kiss_fftr(cfg, audioData.data(), reinterpret_cast<kiss_fft_cpx*>(spec.get()));
+    kiss_fftr_free(cfg);
+
+    // scale transform, and normalize amplitude and phase
+    const std::complex<double> k = std::polar(2.0 / fftSize, -M_PI / 2);
+    for (size_t i = 0; i < specSize; ++i)
+        spec[i] *= k;
+
+    TabulatedHarmonicProfile hp {
+        absl::Span<const std::complex<float>> { spec.get(), specSize }
+    };
+
+    auto wave = std::make_shared<WavetableMulti>(
+        WavetableMulti::createForHarmonicProfile(hp, 1.0));
+
+    _fileWaves[filename] = wave;
+    return true;
+}
+
 } // namespace sfz
diff --git a/src/sfizz/Wavetables.h b/src/sfizz/Wavetables.h
index bdc715bc..6290f01f 100644
--- a/src/sfizz/Wavetables.h
+++ b/src/sfizz/Wavetables.h
@@ -9,10 +9,12 @@
 #include "LeakDetector.h"
 #include "Buffer.h"
 #include <absl/types/span.h>
+#include <absl/container/flat_hash_map.h>
 #include <memory>
 #include <complex>
 
 namespace sfz {
+class FilePool;
 
 class WavetableMulti;
 
@@ -157,8 +159,8 @@ public:
     static WavetableMulti createForHarmonicProfile(
         const HarmonicProfile& hp, double amplitude, unsigned tableSize = config::tableSize, double refSampleRate = 44100.0);
 
-    // create the tiniest wavetable with null content for use with oscillators
-    static WavetableMulti createSilence();
+    // get a tiny silent wavetable with null content for use with oscillators
+    static const WavetableMulti* getSilenceWavetable();
 
 private:
     // get a pointer to the beginning of the N-th table
@@ -185,15 +187,42 @@ private:
 };
 
 /**
- * @brief Holds predefined wavetables.
+ * @brief Holds predefined and loaded wavetables.
  *
  */
 struct WavetablePool {
     WavetablePool();
+
+    /**
+     * @brief Get a file wave. Return a silent table if the wave does not exist yet.
+     * Use createFileWave to preload file waves before calling this function.
+     * This function is real-time safe.
+     *
+     * @param filename the name of the file wave
+     * @return the wavetable, or a silent table
+     */
+    const WavetableMulti* getFileWave(const std::string& filename);
+    /**
+     * @brief Load a file wave from the filepool and use it to create a wavetable.
+     * This function is not real-time safe.
+     *
+     * @param filePool the file pool to use to load the file
+     * @param filename the file name to load
+     * @return true if the wavetable was correctly created (or existed already)
+     */
+    bool createFileWave(FilePool& filePool, const std::string& filename);
+    /**
+     * @brief Removes all the stored file waves from the wavetable pool.
+     */
+    void clearFileWaves();
+
     static const WavetableMulti* getWaveSin();
     static const WavetableMulti* getWaveTriangle();
     static const WavetableMulti* getWaveSaw();
     static const WavetableMulti* getWaveSquare();
+
+private:
+    absl::flat_hash_map<std::string, std::shared_ptr<WavetableMulti>> _fileWaves;
 };
 
 } // namespace sfz