by the way, a mean to get it done without error is to not use runALUTUsingCurrentContext : import Sound.ALUT playSound :: IO () playSound = withProgNameAndArgs runALUT $ \ _ _ -> do buffer1 <- createBuffer $ Sine 440 0 1 buffer2 <- createBuffer HelloWorld [source] <- genOjectNames 1 queueBuffers source [buffer1,buffer2] play [source] sleep 2 return () main = playSound I'm not sure if haskell-cafe will take spaces into account. If not, only 7 lines should be tabulated after do. Does anyone know how to mix buffers ? _________________________________________________________________ Vous voulez savoir ce que vous pouvez faire avec le nouveau Windows Live ? Lancez-vous ! http://www.microsoft.com/windows/windowslive/default.aspx