Every story and comment from the Hacker News API, in a layout borrowed from 2001.
A comment on Finding the genre of a song with Deep Learning.
The creator wrote about it here:
http://blog.echonest.com/post/52385283599/how-we-understand-...
and writes a lot about it on their blog:
http://www.furia.com/page.cgi?terms=noise&type=search
Of course those are going in the other direction, not generating the classification from the data, but it's probably one of the best data sets as far as classifying existing music.
The creator wrote about it here:
http://blog.echonest.com/post/52385283599/how-we-understand-...
and writes a lot about it on their blog:
http://www.furia.com/page.cgi?terms=noise&type=search
Of course those are going in the other direction, not generating the classification from the data, but it's probably one of the best data sets as far as classifying existing music.