A year or two ago (I can’t remember exactly), I went hunting for an application for OS X that would analyze my iTunes library and give me the beats per minute (BPM). I’m a fan of very high tempo tracks, especially while working or running. Unfortunately I only found one application, and it didn’t work too well, and only catalogued a small portion of my collection.

Today I noticed Chris Messina–whose blog is worth reading if only to see examples of great design–mention Tangerine.

Tangerine takes a look at your iTunes library and works out the BPM and Beat Intensity of it’s music. You can then create a playlist that varies in total length, variety of BPM and Intensity, and also pattern (random, single hill, double hill, and single hill alternating). It also allows you to write the BPM to your iTunes library, which allows me to create a few extra Smart Playlists myself.

The application looks sweet, right down to the boxed tangerine with a straw as an icon. It’ll be something that becomes a companion of mine for some time I’d imagine. As soon as Apple launches their Nike+ range of products down here, it’ll be even more valuable.