diff --git a/configure.py b/configure.py
index 1167fa86c..3f91c4e8a 100644
--- a/configure.py
+++ b/configure.py
@@ -745,7 +745,7 @@ def JSystemLib(lib_name, objects):
             Object(Matching,    "JSystem/JAudio/JASChAllocQueue.cpp"),
             Object(NonMatching, "JSystem/JAudio/JASChannel.cpp"),
             Object(NonMatching, "JSystem/JAudio/JASChannelMgr.cpp"),
-            Object(NonMatching, "JSystem/JAudio/JASOscillator.cpp"),
+            Object(Matching,    "JSystem/JAudio/JASOscillator.cpp"),
             Object(Matching,    "JSystem/JAudio/JASDriverTables.cpp"),
             Object(Matching,    "JSystem/JAudio/dspproc.c", extra_cflags="-lang c++ -O4 -func_align 32"),
             Object(Matching,    "JSystem/JAudio/dsptask.c", extra_cflags="-lang c++ -O4 -func_align 32"),
diff --git a/include/JSystem/JAudio/JASOscillator.h b/include/JSystem/JAudio/JASOscillator.h
index d3aaaab94..bf7ee9de4 100644
--- a/include/JSystem/JAudio/JASOscillator.h
+++ b/include/JSystem/JAudio/JASOscillator.h
@@ -9,8 +9,8 @@ namespace JASystem {
         struct Osc_ {
             /* 0x00 */ u8 field_0x0;
             /* 0x04 */ f32 field_0x4;
-            /* 0x08 */ void* table;
-            /* 0x0C */ void* rel_table;
+            /* 0x08 */ s16* table;
+            /* 0x0C */ s16* rel_table;
             /* 0x10 */ f32 field_0x10;
             /* 0x14 */ f32 field_0x14;
         };
@@ -22,18 +22,31 @@ namespace JASystem {
         f32 getOffset();
         bool forceStop();
         bool release();
-        void calc(s16*);
+        f32 calc(s16*);
 
-        /* 0x00 */ const Osc_* field_0x0;
-        /* 0x04 */ u8 field_0x4;
+        const Osc_* getOsc() const { return mOsc; }
+        void setOsc(const Osc_* osc) { mOsc = osc; }
+        BOOL isOsc() { return mOsc != NULL ? TRUE : FALSE; }
+        void releaseDirect(u16 param_0) { mDirectRelease = param_0; }
+        void bankOscToOfs() {}
+        void getEffectorKind() const {}
+        void getOscMode() const {}
+
+        static s16 oscTableForceStop[6];
+        static const f32 relTableSampleCell[17];
+        static const f32 relTableSqRoot[17];
+        static const f32 relTableSquare[17];
+
+        /* 0x00 */ const Osc_* mOsc;
+        /* 0x04 */ u8 mState;
         /* 0x05 */ u8 field_0x5;
-        /* 0x06 */ short field_0x6;
-        /* 0x08 */ f32 field_0x8;
-        /* 0x0C */ f32 field_0xc;
-        /* 0x10 */ f32 field_0x10;
-        /* 0x14 */ f32 field_0x14;
-        /* 0x18 */ u16 field_0x18;
-        /* 0x1C */ f32 field_0x1c;
+        /* 0x06 */ u16 field_0x6;
+        /* 0x08 */ f32 mReleaseRate;
+        /* 0x0C */ f32 mPhase;
+        /* 0x10 */ f32 mTargetPhase;
+        /* 0x14 */ f32 mPhaseChangeRate;
+        /* 0x18 */ u16 mDirectRelease;
+        /* 0x1C */ f32 mInitialReleaseRate;
     };
 }
 
diff --git a/src/JSystem/JAudio/JASChannel.cpp b/src/JSystem/JAudio/JASChannel.cpp
index 18a9ae3b9..09190eb2f 100644
--- a/src/JSystem/JAudio/JASChannel.cpp
+++ b/src/JSystem/JAudio/JASChannel.cpp
@@ -47,7 +47,7 @@ void JASystem::TChannel::init() {
     }
     for (u32 i = 0; i < 4; i++) {
         JUT_ASSERT(155, osc[i]);
-        osc[i]->field_0x0 = NULL;
+        osc[i]->setOsc(NULL);
         osc[i]->init();
     }
     mPauseFlag = 0;
@@ -67,7 +67,7 @@ void JASystem::TChannel::setOscillator(u32 oscnum, TOscillator* param_2) {
 /* 8028B620-8028B6A8       .text setOscInit__Q28JASystem8TChannelFUlPCQ38JASystem11TOscillator4Osc_ */
 void JASystem::TChannel::setOscInit(u32 oscnum, const TOscillator::Osc_* param_2) {
     JUT_ASSERT(183, oscnum < (4));
-    osc[oscnum]->field_0x0 = param_2;
+    osc[oscnum]->setOsc(param_2);
     osc[oscnum]->initStart();
 }
 
@@ -75,27 +75,28 @@ void JASystem::TChannel::setOscInit(u32 oscnum, const TOscillator::Osc_* param_2
 bool JASystem::TChannel::forceStopOsc(u32 numosc) {
     /* Nonmatching */
     JUT_ASSERT(195, numosc < (4));
-    return osc[numosc]->field_0x0 != NULL ? osc[numosc]->forceStop() : false;
+    return osc[numosc]->isOsc() ? osc[numosc]->forceStop() : false;
 }
 
 /* 8028B73C-8028B7D0       .text releaseOsc__Q28JASystem8TChannelFUl */
 bool JASystem::TChannel::releaseOsc(u32 numosc) {
     /* Nonmatching */
     JUT_ASSERT(209, numosc < (4));
-    return osc[numosc]->field_0x0 ? osc[numosc]->release() : false;
+    return osc[numosc]->isOsc() ? osc[numosc]->release() : false;
 }
 
 /* 8028B7D0-8028B850       .text directReleaseOsc__Q28JASystem8TChannelFUlUs */
 void JASystem::TChannel::directReleaseOsc(u32 oscnum, u16 param_2) {
     JUT_ASSERT(224, oscnum < (4));
-    osc[oscnum]->field_0x18 = param_2;
+    osc[oscnum]->releaseDirect(param_2);
 }
 
 /* 8028B850-8028B8E4       .text bankOscToOfs__Q28JASystem8TChannelFUl */
 f32 JASystem::TChannel::bankOscToOfs(u32 oscnum) {
     /* Nonmatching */
     JUT_ASSERT(234, oscnum < (4));
-    return osc[oscnum]->field_0x0 ? osc[oscnum]->getOffset() : 1.0f;
+    // Probably uses inline JASystem::TOscillator::bankOscToOfs
+    return osc[oscnum]->isOsc() ? osc[oscnum]->getOffset() : 1.0f;
 }
 
 /* 8028B8E4-8028BA98       .text effectOsc__Q28JASystem8TChannelFUlf */
@@ -107,14 +108,14 @@ void JASystem::TChannel::effectOsc(u32 oscnum, f32 param_2) {
 int JASystem::TChannel::getOscState(u32 oscnum) const {
     /* Nonmatching */
     JUT_ASSERT(274, oscnum < (4));
-    return osc[oscnum]->field_0x4;
+    return osc[oscnum]->mState;
 }
 
 /* 8028BB14-8028BB98       .text isOsc__Q28JASystem8TChannelFUl */
 BOOL JASystem::TChannel::isOsc(u32 oscnum) {
     /* Nonmatching */
     JUT_ASSERT(284, oscnum < (4));
-    return osc[oscnum]->field_0x0 != 0;
+    return osc[oscnum]->isOsc();
 }
 
 /* 8028BB98-8028BC78       .text copyOsc__Q28JASystem8TChannelFUlPQ38JASystem11TOscillator4Osc_ */
@@ -122,7 +123,7 @@ void JASystem::TChannel::copyOsc(u32 oscnum, TOscillator::Osc_* param_2) {
     /* Nonmatching */
     JUT_ASSERT(295, oscnum < (4));
     if (isOsc(oscnum)) {
-        *param_2 = *osc[oscnum]->field_0x0;
+        *param_2 = *osc[oscnum]->getOsc();
     } else {
         OSReport("osc[%d] is NULL\n", oscnum);
     }
diff --git a/src/JSystem/JAudio/JASOscillator.cpp b/src/JSystem/JAudio/JASOscillator.cpp
index 73455b03e..2c8ec371c 100644
--- a/src/JSystem/JAudio/JASOscillator.cpp
+++ b/src/JSystem/JAudio/JASOscillator.cpp
@@ -4,59 +4,275 @@
 //
 
 #include "JSystem/JAudio/JASOscillator.h"
+#include "JSystem/JAudio/JASDriverIF.h"
+#include "JSystem/JAudio/JASRate.h"
+#include "dolphin/os/OS.h"
+#include "dolphin/types.h"
+#include "math.h"
+
+s16 JASystem::TOscillator::oscTableForceStop[] = {
+    0, 15, 0,
+    15, 0, 0
+};
+
+const f32 JASystem::TOscillator::relTableSampleCell[] = {
+    1.0f, 0.970489f, 0.781274f, 0.546281f, 0.399792f, 0.289315f,
+    0.212104f, 0.157476f, 0.112613f, 0.0817896f, 0.0579852f, 0.0436415f,
+    0.0308237f, 0.0237129f, 0.0152593f, 0.00915555f,
+};
+
+// relTableSqRoot[i] = pow(1 - i/16, 2)
+const f32 JASystem::TOscillator::relTableSqRoot[] = {
+    1.0f, 0.878906f, 0.765625f, 0.660156f,
+    0.5625f, 0.472656f, 0.390625f, 0.316406f,
+    0.25f, 0.191406f, 0.140625f, 0.0976562f,
+    0.0625f, 0.0351562f, 0.015625f, 0.00390625,
+};
+
+// relTableSquare[i] = sqrt(1 - i/16)
+const f32 JASystem::TOscillator::relTableSquare[] = {
+    1.0f, 0.968246f, 0.935414f, 0.901388f,
+    0.866025f, 0.829156f, 0.790569f, 0.75f,
+    0.707107f, 0.661438f, 0.612372f, 0.559017f,
+    0.5f, 0.433013f, 0.353553f, 0.25f,
+};
 
 /* 8028DE94-8028DECC       .text init__Q28JASystem11TOscillatorFv */
 void JASystem::TOscillator::init() {
-    field_0x0 = NULL;
-    field_0x4 = 1;
+    mOsc = NULL;
+    mState = 1;
     field_0x5 = 0;
     field_0x6 = 0;
-    field_0x8 = 0.0f;
-    field_0xc = 0.0f;
-    field_0x10 = 0.0f;
-    field_0x14 = 0.0f;
-    field_0x18 = 0;
-    field_0x1c = 0.0f;
+    mReleaseRate = 0.0f;
+    mPhase = 0.0f;
+    mTargetPhase = 0.0f;
+    mPhaseChangeRate = 0.0f;
+    mDirectRelease = 0;
+    mInitialReleaseRate = 0.0f;
 }
 
 /* 8028DECC-8028DF2C       .text initStart__Q28JASystem11TOscillatorFv */
 void JASystem::TOscillator::initStart() {
-    field_0x4 = 2;
-    field_0x18 = 0;
-    if (!field_0x0 || !field_0x0->table) {
-        field_0xc = 0.0f;
+    mState = 2;
+    mDirectRelease = 0;
+    if (mOsc == NULL || !mOsc->table) {
+        mPhase = 0.0f;
         return;
     }
     field_0x6 = 0;
-    field_0x8 = 0.0f;
-    field_0x10 = 0.0f;
-    field_0x18 = 0;
-    field_0x8 -= field_0x0->field_0x4;
+    mReleaseRate = 0.0f;
+    mTargetPhase = 0.0f;
+    mDirectRelease = 0;
+    mReleaseRate -= mOsc->field_0x4;
 }
 
 /* 8028DF2C-8028E070       .text getOffset__Q28JASystem11TOscillatorFv */
 f32 JASystem::TOscillator::getOffset() {
-    /* Nonmatching */
+    if (mOsc == NULL) {
+        OSReport("----- Oscillator is NULL\n");
+        mPhase = 1.0f;
+        return 1.0f;
+    }
+
+    switch (mState) {
+    case 0:
+        return 1.0f;
+    case 3:
+        return mOsc->field_0x14 + (mPhase * mOsc->field_0x10);
+
+    case 1:
+        mState = 2;
+        OSReport("----- Error Initialize\n");
+        /* Fallthrough */
+    default:
+        s16* var_r4;
+        if (mState == 4) {
+            var_r4 = mOsc->rel_table;
+        } else if (mState == 5) {
+            var_r4 = oscTableForceStop;
+        } else {
+            var_r4 = mOsc->table;
+        }
+
+        if (var_r4 == NULL && mState != 6) {
+            mPhase = 1.0f;
+            return 1.0f;
+        }
+
+        if (mState == 5) {
+            mReleaseRate -= 1.0f;
+        } else {
+            mReleaseRate -= mOsc->field_0x4;
+        }
+
+        return calc(var_r4);
+
+    }
 }
 
 /* 8028E070-8028E0AC       .text forceStop__Q28JASystem11TOscillatorFv */
 bool JASystem::TOscillator::forceStop() {
-    if (field_0x4 == 5) {
+    if (mState == 5) {
         return false;
     }
     field_0x6 = 0;
-    field_0x8 = 0.0f;
-    field_0x10 = field_0xc;
-    field_0x4 = 5;
+    mReleaseRate = 0.0f;
+    mTargetPhase = mPhase;
+    mState = 5;
     return true;
 }
 
 /* 8028E0AC-8028E238       .text release__Q28JASystem11TOscillatorFv */
 bool JASystem::TOscillator::release() {
-    /* Nonmatching */
+    if (mState == 5) {
+        return false;
+    }
+
+    if (mOsc->table != mOsc->rel_table) {
+        field_0x6 = 0;
+        mReleaseRate = 0.0f;
+        mTargetPhase = mPhase;
+    }
+
+    if (mOsc->rel_table == NULL && mDirectRelease == 0) {
+        mDirectRelease = 0x10;
+    }
+
+    if (mDirectRelease != 0) {
+        mState = 6;
+        field_0x5 = (mDirectRelease >> 14) & 3;
+
+        f32 temp_f31 = mDirectRelease & 0x3FFF;
+        temp_f31 *= ((Kernel::getDacRate() / 80.0f) / 600.0f);
+        temp_f31 /= Driver::getUpdateInterval();
+        mReleaseRate = temp_f31;
+
+        if (mReleaseRate < 1.0f) {
+            mReleaseRate = 1.0f;
+        }
+
+        mInitialReleaseRate = mReleaseRate;
+        mTargetPhase = 0.0f;
+        if (field_0x5 == 0) {
+            mPhaseChangeRate = (mTargetPhase - mPhase) / mReleaseRate;
+        } else {
+            mPhaseChangeRate = mTargetPhase - mPhase;
+        }
+    } else {
+        mState = 4;
+    }
+
+    return true;
 }
 
 /* 8028E238-8028E5EC       .text calc__Q28JASystem11TOscillatorFPs */
-void JASystem::TOscillator::calc(s16*) {
-    /* Nonmatching */
+f32 JASystem::TOscillator::calc(s16* i_table) {
+    while (mReleaseRate <= 0.0f) {
+        int idx = field_0x6 * 3;
+        mPhase = mTargetPhase;
+        if (mState == 6) {
+            mState = 0;
+            break;
+        }
+
+        s16 envMode  = i_table[idx];
+        s16 envTime  = i_table[idx + 1];
+        s16 envValue = i_table[idx + 2];
+
+        if (envMode == 13) {
+            field_0x6 = envValue;
+            continue;
+        }
+
+        if (envMode == 15) {
+            mState = 0;
+            break;
+        }
+
+        if (envMode == 14) {
+            mState = 3;
+            return mOsc->field_0x14 + mPhase * mOsc->field_0x10;
+        }
+
+        field_0x5 = envMode;
+
+        if (envTime == 0) {
+            mTargetPhase = envValue / 32768.0f;
+            field_0x6 += 1;
+            continue;
+        }
+
+        mReleaseRate = envTime * ((Kernel::getDacRate() / 80.0f) / 600.0f) / Driver::getUpdateInterval();
+        mInitialReleaseRate = mReleaseRate;
+        mTargetPhase = envValue / 32768.0f;
+
+        if (field_0x5 == 0) {
+            mPhaseChangeRate = (mTargetPhase - mPhase) / mReleaseRate;
+        } else {
+            mPhaseChangeRate = mTargetPhase - mPhase;
+        }
+
+        field_0x6 += 1;
+    }
+
+    if (mOsc->field_0x10 == 0.0f) {
+        return mOsc->field_0x14;
+    }
+
+
+    f32 temp_f31 = 0.0f;
+    f32 newPhase;
+    if (mInitialReleaseRate == 0.0) { // Developer probably forgot the f suffix
+        newPhase = mTargetPhase;
+        mPhase = mTargetPhase; 
+    } else {
+        if (field_0x5 == 0 || (temp_f31 = mPhaseChangeRate) == 0.0f) {
+            newPhase = mTargetPhase - (mPhaseChangeRate * mReleaseRate);
+            mPhase = newPhase;
+        } else if (field_0x5 == 3 || field_0x5 == 1 || field_0x5 == 2) {
+            const f32* table = NULL;
+
+            switch (field_0x5) {
+            case 3:
+                table = relTableSampleCell;
+                break;
+            case 1:
+                table = relTableSquare;
+                break;
+            case 2:
+                table = relTableSqRoot;
+                break;
+            }
+
+            f32 fIdx;
+
+            if (temp_f31 < 0.0f) {
+                fIdx = 16.0f * (1.0f - (mReleaseRate / mInitialReleaseRate));
+            } else {
+                fIdx = 16.0f * (mReleaseRate / mInitialReleaseRate);
+            }
+
+            u32 idx = fIdx;
+            f32 prop = fIdx - (f32)idx;
+            if (idx >= 16) {
+                idx = 15;
+                prop = 1.0f;
+            }
+
+            f32 valAbs = std::fabsf(temp_f31 * (prop * (table[idx + 1] - table[idx]) + table[idx]));
+
+            if (mPhaseChangeRate < 0.0f) {
+                newPhase = mTargetPhase + valAbs;
+            } else {
+                newPhase = mTargetPhase - (mPhaseChangeRate - valAbs);
+            }
+
+            mPhase = newPhase;
+        } else {
+            newPhase = mTargetPhase - (temp_f31 * mReleaseRate);
+            mPhase = newPhase;
+        }
+    }
+
+    return newPhase * mOsc->field_0x10 + mOsc->field_0x14;
 }
diff --git a/src/JSystem/JAudio/JASPlayer_impl.cpp b/src/JSystem/JAudio/JASPlayer_impl.cpp
index 6252b85bc..152412cfa 100644
--- a/src/JSystem/JAudio/JASPlayer_impl.cpp
+++ b/src/JSystem/JAudio/JASPlayer_impl.cpp
@@ -65,15 +65,15 @@ const JASystem::TOscillator::Osc_ JASystem::Player::sAdsrDef = {
 };
 
 const JASystem::TOscillator::Osc_ JASystem::Player::sEnvelopeDef = {
-    0, 1.0f, NULL, &sRelTable, 1.0f, 0.0f
+    0, 1.0f, NULL, sRelTable, 1.0f, 0.0f
 };
 
 const JASystem::TOscillator::Osc_ JASystem::Player::sVibratoDef = {
-    1, 0.5f, &sVibTable, &sVibTable, 0.0f, 1.0f
+    1, 0.5f, sVibTable, sVibTable, 0.0f, 1.0f
 };
 
 const JASystem::TOscillator::Osc_ JASystem::Player::sTremoroDef = {
-    0, 0.5f, &sTreTable, &sTreTable, 0.0f, 1.0f
+    0, 0.5f, sTreTable, sTreTable, 0.0f, 1.0f
 };
 
 s16 JASystem::Player::CUTOFF_TO_IIR_TABLE[] = {
diff --git a/src/JSystem/JAudio/JASTrack.cpp b/src/JSystem/JAudio/JASTrack.cpp
index 69809c617..78b323b8f 100644
--- a/src/JSystem/JAudio/JASTrack.cpp
+++ b/src/JSystem/JAudio/JASTrack.cpp
@@ -325,7 +325,7 @@ void JASystem::TTrack::overwriteOsc(TChannel* param_1) {
             }
             param_1->copyOsc(r28, &field_0x2cc[i]);
         } else if (var1 & 4) {
-            void* var4 = field_0x2cc[i].rel_table;
+            s16* var4 = field_0x2cc[i].rel_table;
             if (!param_1->isOsc(r28)) {
                 JUT_WARN(603, "%s", "cannot copy osc");
                 continue;
@@ -390,7 +390,7 @@ void JASystem::TTrack::oscSetupFull(u8 param_1, u32 param_2, u32 param_3) {
         if (param_2 == 0) {
             field_0x2cc[var1].table = NULL;
         }
-        field_0x2cc[var1].table = mSeqCtrl.mRawFilePtr + param_2;
+        field_0x2cc[var1].table = (s16*)(mSeqCtrl.mRawFilePtr + param_2);
     }
     if (!var5) {
         return;
@@ -398,7 +398,7 @@ void JASystem::TTrack::oscSetupFull(u8 param_1, u32 param_2, u32 param_3) {
     if (param_3 == 0) {
         field_0x2cc[var1].rel_table = Player::sRelTable;
     }
-    field_0x2cc[var1].rel_table = mSeqCtrl.mRawFilePtr + param_2;
+    field_0x2cc[var1].rel_table = (s16*)(mSeqCtrl.mRawFilePtr + param_2);
 }
 
 /* 802817E4-80281850       .text oscSetupSimpleEnv__Q28JASystem6TTrackFUcUl */
@@ -406,10 +406,10 @@ void JASystem::TTrack::oscSetupSimpleEnv(u8 param_1, u32 param_2) {
     switch (param_1) {
     case 0:
         field_0x2cc[0] = Player::sEnvelopeDef;
-        field_0x2cc[0].table = mSeqCtrl.mRawFilePtr + param_2;
+        field_0x2cc[0].table = (s16*)(mSeqCtrl.mRawFilePtr + param_2);
         break;
     case 1:
-        field_0x2cc[0].rel_table = mSeqCtrl.mRawFilePtr + param_2;
+        field_0x2cc[0].rel_table = (s16*)(mSeqCtrl.mRawFilePtr + param_2);
         break;
     }
 }