Given the lyrics of a song, algorithms can relatively easily figure out if it’s a Christmas song, a love song, if it contains explicit lyrics, or simply just identify the language it’s sung in. Such algorithms could be used to improve music discovery, recommendation, and playlist generation.
Personally I think lyrics are one of the most important parts of a song. If I don’t like the lyrics, I won’t like the song. I’d love to have lyrics on my display while listening to a song, I’d love to be able to search or listening to music with similar lyrics, there is so much that would be so easy to do if the lyrics would be available, but they are not.
There is an interesting article in the WSJ by Jason Fry on this, which I stumbled upon via this post on the Lefstez letter (which also contains some interesting thoughts on the topic). Sometimes I just don't understand how far detached some parts of the music industry have become from the artists and their fans. And I also wonder how much longer those who are battling to enforce ancient business models will survive.