1) Completely unplug the Sonos for 30 seconds, then plug it back in.
2) Remove and re-add Rhapsody.
Don't worry, your library and playlists are safe.
3) Contact Sonos support at http://www.sonos.com/support or 800-680-2345
Artist and record labels decide what songs are available on Rhapsody. Rights to songs can change over time. Some songs that were once available may disappear or show as grayed-out if the right's holder requests we remove them. Many songs that are removed are gone temporarily, and are eventually returned to our catalog. We're adding thousands of songs each week, so check back often. Want to request we add an artist or song? Let us know.