BestPractice is described as 'tool especially for musicians to slow down or speed up music, either from a file or directly from a CD while keeping the pitch at the correct height. On the other hand the pitch of the music can be changed without affecting the temp' and is an app in the Audio & Music category. There are three alternatives to BestPractice for a variety of platforms, including iPad, iPhone, Mac, Windows and PortableApps.com. The best alternative is Amazing Slow Downer, which is free. Other great apps like BestPractice are AudioScrub (Paid) and PaulStretch (Free, Open Source).
Change the speed of the music - from 20% (one fifth speed) to 200% (double speed) without changing the pitch. Wrong key? Change the pitch in semi-tones - at full or changed speed. Out of tune? Adjust the pitch in cents (100ths of a semi-tone) to suit your instrument.
This is a program for stretching the audio. It is suitable only for extreme sound stretching of the audio (like 50x) and for applying special effects by "spectral smoothing" the sounds. It can transform any sound/music to a texture.