This is really awesome.<p>One thing that I think could be done better would be to display the BPM Deviation by percentage instead of a hard tempo.<p>This is especially important when there is ambiguity over what the tempo actually is. Is this song 90 BPM or 180? That question is pretty hard for a computer to tell, and two great musicians might tell you different answers. It's pretty subjective.<p>Here's an example of two takes of a slow rubato jazz piece. The computer analyzes one using a tempo of 169 BPM and the other at 91. It's the same song, and a very similar tempo. But the one rated faster looks much more erratic because the deviation isn't displayed as a percentage.<p><a href="http://labs.echonest.com/click/?trackId=TRFQMHM123E8585C4A&artist=John+Coltrane&title=06.+Naima" rel="nofollow">http://labs.echonest.com/click/?trackId=TRFQMHM123E8585C4A&#...</a><p><a href="http://labs.echonest.com/click/?trackId=TRGHGWJ123E858DF63&artist=John+Coltrane&title=09.+Naima+%28alternate%29" rel="nofollow">http://labs.echonest.com/click/?trackId=TRGHGWJ123E858DF63&#...</a>
This is fascinating. Of course most modern music is generated with click tracks, if for nothing else than it makes it easier to edit in Pro Tools, since each track will be aligned with a beat grid, and you can literally cut and paste entire bars of music.<p>This has more to do with the modern way of generating music - get four or five takes of the song from each musician, take the best bars and phrases from each one, and put them all together. Maybe Britney had a great take on the second take of the chorus, so you just copy/paste that 5 times and now every time the chorus plays it sounds perfect. Maybe the instrumental solo was perfect the third time, so let's use that one.<p>This also makes you have great appreciation for those bands that recorded music before the advent of modern multi-track recording software, and were somehow dedicated enough to get that one perfect take where everyone in the band did great and nobody made a mistake.
The guys at echonest seem to slip through the cracks a bit on HN, but they are doing some amazing stuff. I encourage anyone with an interest in music to check out the API.
Those are some really fascinating results. Although now and then you'll see machine-like scores when <i>there's no way</i>. Most interesting is to look at old-timers that boozed it up alot... tempos ALL over!<p><a href="http://labs.echonest.com/click/?trackId=TREHNVI1254846046C&artist=Jerry+Lee+Lewis&title=Good+Golly+Miss+Molly" rel="nofollow">http://labs.echonest.com/click/?trackId=TREHNVI1254846046C&#...</a>
<i>It looks like Neil Peart uses a click track on Stick it out</i><p>or he could just be rock solid.<p>I wonder how well Tico Torres and Billy Cobham (great drummers and time-keepers) backed tracks fare, especially one from the 80's and early 90's when computer editors were less common.