diff --git a/CMakeLists.txt b/CMakeLists.txt
index e5066d1..0ce08f5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -47,6 +47,10 @@ add_library(sonobulus_core STATIC
     src/synth/KeyboardController.cpp
     src/synth/MidiController.cpp
     src/synth/NoteQueue.cpp
+    src/synth/Scope.cpp
+    src/synth/Synth.cpp
+    src/synth/Voice.cpp
+    src/synth/Instrument.cpp
 )
 target_link_libraries(sonobulus_core PRIVATE
     Qt6::Core
diff --git a/src/synth/Instrument.cpp b/src/synth/Instrument.cpp
new file mode 100644
index 0000000..e69de29
diff --git a/src/synth/Instrument.hpp b/src/synth/Instrument.hpp
new file mode 100644
index 0000000..ed86b53
--- /dev/null
+++ b/src/synth/Instrument.hpp
@@ -0,0 +1,15 @@
+
+#pragma once
+
+// an instrument is our state space model. it calculates discrete samples as a function of time, the current states, and the inputs
+// an instrumeent is owned by a voice
+class Instrument {
+
+public:
+
+    Instrument() = default;
+    ~Instrument() = default;
+
+private:
+
+};
\ No newline at end of file
diff --git a/src/synth/Scope.cpp b/src/synth/Scope.cpp
new file mode 100644
index 0000000..e69de29
diff --git a/src/synth/Scope.hpp b/src/synth/Scope.hpp
new file mode 100644
index 0000000..904fb74
--- /dev/null
+++ b/src/synth/Scope.hpp
@@ -0,0 +1,27 @@
+
+#pragma once
+
+#include <vector>
+#include <atomic>
+
+class ScopeBuffer {
+
+public:
+
+    ScopeBuffer(size_t size);
+    ~ScopeBuffer() = default;
+
+    void push(float sample);
+    void read(std::vector<float>& out);
+
+private:
+
+    std::vector<float> buffer_;
+    std::atomic<size_t> writeIndex_{0};
+
+    size_t trigger_ = 0;
+    uint32_t wavelgnth = 400;
+
+    bool spinLock_ = false;
+
+};
diff --git a/src/synth/Synth.cpp b/src/synth/Synth.cpp
new file mode 100644
index 0000000..e69de29
diff --git a/src/synth/Synth.hpp b/src/synth/Synth.hpp
new file mode 100644
index 0000000..686be07
--- /dev/null
+++ b/src/synth/Synth.hpp
@@ -0,0 +1,35 @@
+
+#pragma once
+
+#include "ConfigService.hpp"
+#include "LoggerService.hpp"
+#include "NoteQueue.hpp"
+#include "Voice.hpp"
+#include "Scope.hpp"
+
+#include <vector>
+
+class Synth {
+
+public:
+
+    Synth(ConfigService* config, LoggerService* logger, ScopeBuffer* scope);
+    ~Synth();
+
+    void process(float* out, size_t nFrames, uint32_t sampleRate);
+    void handleNoteEvent(const NoteEvent& event);
+
+private:
+
+    Voice* findFreeVoice();
+    Voice* findVoiceByNote(uint8_t note);
+
+    std::vector<uint8_t> sustainedNotes_;
+
+    // voices
+    static constexpr size_t MAX_VOICES = 32;
+    std::array<Voice, MAX_VOICES> voices_;
+
+    ScopeBuffer* scope_ = nullptr;
+
+}
\ No newline at end of file
diff --git a/src/synth/Voice.cpp b/src/synth/Voice.cpp
new file mode 100644
index 0000000..e69de29
diff --git a/src/synth/Voice.hpp b/src/synth/Voice.hpp
new file mode 100644
index 0000000..994e814
--- /dev/null
+++ b/src/synth/Voice.hpp
@@ -0,0 +1,36 @@
+
+#pragma once
+
+#include <stdint.h>
+
+#include "Instrument.hpp"
+
+// a voice is a tone generator that the synth uses for polyphony
+// the synth mixes multiple voices together into a polyphonic audio. calculations for samples are handled in the instrument
+class Voice {
+
+public:
+
+    Voice() = default;
+    ~Voice() = default;
+
+    void noteOn(int8_t midiNote, float velocity);
+    void noteOff();
+    bool isActive();
+
+    float process(bool& scopeTrigger);
+    uint8_t note() { return note_; }
+
+private:
+
+    float sampleRate_ = 44100.0f;
+
+    inline float noteToFrequency(uint8_t note);
+    
+    uint8_t note_ = 0;
+    float velocity_ = 1.0f;
+    bool active_ = false;
+
+    Instrument* instrument;
+
+};