Here's a link to Sabine's description of this device, from which the description below is taken: http://www.sabine.com/

The Sabine BACKTRAK BT-300 is a powerful digital sampler that can capture up to 30 seconds of audio material from a stereo radio, cassette, CD player or any line level instrument output (via appropriate cable). Play back your recorded material over and over at your choice of 4 speeds - all without changing the pitch! The best part is, you can jam along during playback while listening privately through headphones or through an amplifier!

The BACKTRAK BT-300 has 4 playback speeds (full speed, 2/3 speed, 1/2 speed, 1/3 speed). These speeds allow you to slow your recorded sample while maintaining the "key" or "pitch" in which the original was recorded. This powerful feature lets you slow down parts or phrases of songs so that you can "decode" and learn them. Before long, you'll decode and master the most difficult musical passages. For lyrics, the BT-300 lets you slow down a wordy section so you can hear each lyric at a speed you can understand. You can even use the sample playback capabilities of the BACKTRAK during a performance, adding a dimension of sound effects that, until now, you never thought possible.

The best internet price I can find on this unit is c $80. I'll sell it for $55, including shipping. Email me at acorvid@yahoo.com.