i've been looking for one of these for a long time now. this is a great tool if you want to play / sing along to your favorite tunes.

* Speed up or slow down the music tempo without affecting the music key (pitch)
* Change the music key (pitch) without affecting the tempo
* Change the music "speed" (playback rate) as if vinyl records were played at higher or lower speeds than rated
* Do all of these at the same time.

best of all, the free version is fully functional :)