If I was you I'd integrate my product much more closely into FB as well. At the moment the content on your FB page doesn't give anyone much reason to "like" it.

I presume you're generating a stream of audio recommendations for your iPhone app, so why not publish them to Facebook as well. Have each recommendation (or a subset if there's lots) be a story on your Facebook page so users can "like" and discuss an individual recommendation (and push it to their friend stream) as well.

Here's how I do it for my web comic:

http://www.facebook.com/theoryofgeek

Here's how The Economist do it:

http://www.facebook.com/TheEconomist

If you're a content provider your Facebook page should be much more than news about your company.