Terrence wrote: There's a fundamental difference between MIDI files and MP3/WAV etc files. MIDI files contain a series of note on / note off messages. Its a bit like electronic sheet music and hence very easy to transpose. MP3 and WAV (and all the others) are digital recordings of the sounds. There is no note information. If you are willing to live with the music slow as you transpose done, or speeding up as you transpose up then it should be possible to code something up with Secret Rabbit Code http://www.mega-nerd.com/SRC/ If you want to maintain speed as you modify pitch then that becomes significantly harder especially if you want to transpose more than a semitone or so. My advice is transpose the MIDI file. Thats much easier. Erik -- +-----------------------------------------------------------+ Erik de Castro Lopo +-----------------------------------------------------------+ Question #10342: Ruling on a Muslim eating with a kaafir http://islamqa.com/index.php?ln=eng&ds=qa&lv=browse&QR=10342&am…