diff --git a/src/sfizz/FilePool.cpp b/src/sfizz/FilePool.cpp
index d5471a12..59a2047a 100644
--- a/src/sfizz/FilePool.cpp
+++ b/src/sfizz/FilePool.cpp
@@ -274,7 +274,7 @@ 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 +313,12 @@ 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 +353,7 @@ 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;
diff --git a/src/sfizz/FilePool.h b/src/sfizz/FilePool.h
index c75e6c75..dfebd5b1 100644
--- a/src/sfizz/FilePool.h
+++ b/src/sfizz/FilePool.h
@@ -55,7 +55,7 @@ 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 +69,30 @@ 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);
diff --git a/src/sfizz/Region.cpp b/src/sfizz/Region.cpp
index 8d8f14ee..4f05f314 100644
--- a/src/sfizz/Region.cpp
+++ b/src/sfizz/Region.cpp
@@ -98,6 +98,9 @@ bool sfz::Region::parseOpcode(const Opcode& opcode)
     // Wavetable oscillator
     case hash("oscillator_phase"):
         setValueFromOpcode(opcode, oscillatorPhase, Default::oscillatorPhaseRange);
+    case hash("oscillator"):
+        if (auto value = readBooleanFromOpcode(opcode))
+            oscillator = *value;
         break;
 
     // Instrument settings: voice lifecycle
diff --git a/src/sfizz/Region.h b/src/sfizz/Region.h
index 3ef284d0..ebacc207 100644
--- a/src/sfizz/Region.h
+++ b/src/sfizz/Region.h
@@ -228,6 +228,7 @@ struct Region {
 
     // Wavetable oscillator
     float oscillatorPhase { Default::oscillatorPhase };
+    bool oscillator = false;
 
     // Instrument settings: voice lifecycle
     uint32_t group { Default::group }; // group
diff --git a/src/sfizz/Synth.cpp b/src/sfizz/Synth.cpp
index 930e1c9e..e370fc79 100644
--- a/src/sfizz/Synth.cpp
+++ b/src/sfizz/Synth.cpp
@@ -306,6 +306,7 @@ bool sfz::Synth::loadSfzFile(const fs::path& file)
         return false;
 
     resources.filePool.setRootDirectory(parser.originalDirectory());
+    resources.wavePool.clearFileWaves();
 
     auto currentRegion = regions.begin();
     auto lastRegion = regions.rbegin();
@@ -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 +361,9 @@ bool sfz::Synth::loadSfzFile(const fs::path& file)
             if (!resources.filePool.preloadFile(region->sample, maxOffset))
                 removeCurrentRegion();
         }
+        else if (region->oscillator && !region->isGenerator()) {
+            resources.wavePool.createFileWave(resources.filePool, region->sample);
+        }
 
         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..2b150b42 100644
--- a/src/sfizz/Voice.cpp
+++ b/src/sfizz/Voice.cpp
@@ -58,7 +58,19 @@ void sfz::Voice::startVoice(Region* region, int delay, int number, uint8_t value
             break;
         }
         waveOscillator.setWavetable(wave);
+    } else if (region->oscillator) {
+        const WavetableMulti* wave = resources.wavePool.getFileWave(region->sample);
+        waveOscillator.setWavetable(wave);
+    } else {
+        currentPromise = resources.filePool.getFilePromise(region->sample);
+        if (currentPromise == nullptr) {
+            reset();
+            return;
+        }
+        speedRatio = static_cast<float>(currentPromise->sampleRate / this->sampleRate);
+    }
 
+    if (region->oscillator || region->isGenerator()) {
         float phase;
         const float phaseParam = region->oscillatorPhase;
         if (phaseParam >= 0) {
@@ -69,14 +81,8 @@ void sfz::Voice::startVoice(Region* region, int delay, int number, uint8_t value
             phase = phaseDist(Random::randomGenerator);
         }
         waveOscillator.setPhase(phase);
-    } else {
-        currentPromise = resources.filePool.getFilePromise(region->sample);
-        if (currentPromise == nullptr) {
-            reset();
-            return;
-        }
-        speedRatio = static_cast<float>(currentPromise->sampleRate / this->sampleRate);
     }
+
     pitchRatio = region->getBasePitchVariation(number, value);
 
     baseVolumedB = region->getBaseVolumedB(number);
@@ -294,7 +300,7 @@ 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..9576af8a 100644
--- a/src/sfizz/Wavetables.cpp
+++ b/src/sfizz/Wavetables.cpp
@@ -5,9 +5,9 @@
 // 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 {
 
@@ -279,6 +279,31 @@ 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 +338,65 @@ 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();
+}
+
+const WavetableMulti* WavetablePool::createFileWave(FilePool& filePool, const std::string& filename)
+{
+    if (const WavetableMulti* wave = getFileWave(filename))
+        return wave;
+
+    if (!filePool.preloadFile(filename, 0))
+        return nullptr;
+
+    FilePromisePtr fp = filePool.getFilePromise(filename);
+    if (!fp)
+        return nullptr;
+
+    fp->waitCompletion();
+    if (fp->dataStatus == FilePromise::DataStatus::Error)
+        return nullptr;
+
+    // use 1 channel only, maybe warn if file has more channels
+    auto audioData = fp->fileData.getSpan(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 wave.get();
+}
+
 } // namespace sfz
diff --git a/src/sfizz/Wavetables.h b/src/sfizz/Wavetables.h
index bdc715bc..30640e16 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;
 
@@ -185,15 +187,23 @@ private:
 };
 
 /**
- * @brief Holds predefined wavetables.
+ * @brief Holds predefined and loaded wavetables.
  *
  */
 struct WavetablePool {
     WavetablePool();
+
+    const WavetableMulti* getFileWave(const std::string& filename);
+    const WavetableMulti* createFileWave(FilePool& filePool, const std::string& filename);
+    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