diff --git a/Controller.h b/Controller.h
index 8fe1b9f04..1ce91c45b 100644
--- a/Controller.h
+++ b/Controller.h
@@ -21,7 +21,7 @@
 	Semaphore *ioSemaphore;
 	
 	NSMutableArray *amountConverted;
-	unsigned int amountPlayed; //when amountPlayed > amountConverted[0], amountPlayed -= amountConverted[0], pop(amountConverted[0])
+	unsigned int amountPlayed; //when amountPlayed > amountConverted[0], amountPlayed -= amountConverted[0], pop(amountConverted[0]), song changed
 }
 
 - (void)convertedAmount:(int)amount; //called by converter...same thread?
diff --git a/Converter.m b/Converter.m
index ce5651e8b..52ff2dd2a 100644
--- a/Converter.m
+++ b/Converter.m
@@ -81,11 +81,16 @@ static OSStatus ACInputProc(AudioConverterRef inAudioConverter, UInt32* ioNumber
 	ioData.mBuffers[0].mNumberChannels = [[soundController output] format].mChannelsPerFrame;
 	ioData.mNumberBuffers = 1;
 	
+	[[soundController inputLock] lock];
+	
 	err = AudioConverterFillComplexBuffer(converter, ACInputProc, &[[soundController input] format], &ioNumberFrames, &ioData, NULL);
 	if (err != noErr)
 		DBLog(@"Converter error: %i", err);
 	
-	[[soundController inputBuffer] didReadLength:(ioNumberFrames * [[[soundController input] format].mBytesPerFrame]);
+	[[soundController input] buffer] didReadLength:(ioNumberFrames * [[[soundController input] format].mBytesPerFrame]);
+	
+	[[soundController inputLock] unlock];
+	
 	[[soundController ioSemaphore] signal];
 	
 	return ioData.mBuffers[0].mDataByteSize;
diff --git a/InputController.m b/InputController.m
index dda426d94..c467b780f 100644
--- a/InputController.m
+++ b/InputController.m
@@ -13,7 +13,7 @@
 
 - (void)play
 {
-	[SoundFile open:filename];
+	[soundFile open:filename];
 }
 
 @end