As a follow-up to a previous post I found this Inside The Net podcast on the Pandora music recommendation system. In the interview Tim Westergren, from Pandora, gives a few facts and figures on the system:
- There are 400 aspects in their taxonomy. And, for example, the vocal aspect includes the amount of vibrato, the vocal range and the "twiddlyness" (my words).
- To categorise music they employ people with music degrees and provide 40 hours of training on the taxonomy.
- It takes between 20 and 30 minutes to describe a song.
- They add 7000-8000 songs per month and, in total, describe around 15000 artists with 100,000s songs. In contrast there are typically 50,000 new albums per year in the US.