Rapid Evolution is an advanced harmonic music library tool for DJs, designed to be used while you mix. It helps profile your songs by saving important properties, such as the BPM, key, time signature, styles, comments, and more. You can then instantly see which songs are within BPM range, in key harmonically and in similar styles. More importantly, it lets you save comments and information about each individual mix you come up with. It aims to help properly utilizing music knowledge and harmonic mixing theory to create better mixes. Use it to enhance your knowledge of your own music and remember the important details of what you do. The software includes automatic BPM and key detection, as well as tools to determine this information yourself.
You can download this software dierectly from: http://www.mixshare.com
The site also features a wiki that teaches you some musical theory.
I'm using this software myself and, what is more, it is completely FREE. Check it out.
Another program that works in a similar way is Mixed In Key, a Windows and Macintosh software that enables you to use a DJ technique called harmonic mixing.
Mixed In Key scans your MP3 and WAV files and shows you which songs are harmonically-compatible. With this information, you can eliminate key clashes from your DJ sets.Mixed In Key will charge 58 us $ to download their software.
Are you familiar with other similar programs? Please let us know.