According to rankings from Inside Facebook, music-related pages make up almost 1/3 of Facebook’s most popular pages. Music apps, however, have failed to become similarly popular. In fact, RootMusic is the only one music-related app in the site’s top 50, and that really only shows us what we already know – that music fan pages were very popular on Facebook.

Apps are where money is made on the social network itself, and the music industry needs to learn how to better take advantage of them.

For one, the focus of most music apps is contrary to the site’s core socialness. If we extend our search of Facebook’s most popular apps and look at Spotify and Pandora as examples, the central activity is passive listening. Sure, they have sharing features, but that just takes a second and then the user is done. Without any sort of attractant for users to use Facebook as a basic music player, there’s little incentive for repeat visits or extended use.

Fans love musicians on Facebook, but we need to create more and better apps that leverage the social entertainment aspect of the site before we can deliver a music-app product fans are happy to pay for and not just chat about.

Apps that have proven incredibly popular on Facebook are social casual games. They’re fun, sometimes addictive, and with social as part of their core, they get a lot more play time than other apps. The apps themselves keep users coming back to play again while also encouraging them to share with friends – who will come back and play again.

For music apps to crack Facebook’s top rankings, they need to take on more of the characteristics that keep people engaged for hours. And these apps needn’t be specific to a particular artist or even genre. Keep a look out for how MXP4 is solving this problem in 2011!