varispeed control

[plutonia]

was recording vocals and wanted to sing along at slower speed so that vocal is pitched up when i return track to original speed; the varispeed cassete recorder trick. there are no daw's that do this directly, though there are ways to achieve it using pitch shifers etc

i was wondering how easy it would be to integrate a control (like the 'swing' control in mulab) that does this while hiding all pitching etc thats going on in background and pitches up/down the newly recorded track when you return the song to its original higher or lower bpm.

would be fun and easy way to do it and put grin on faces of those of us that have used cassette 4 tracks.