Okay reading through the rhythmbox info and help. The only way you can create a playlist and therefore play the audio is by selecting a track from the library or audio source. Therefore the ability to play a track directly doesn't exist which is obviously why the gnome team use totem as the default player for audio.
As a result of this research there is currently nothing that the Ubuntu team can do about this situation. My advice is to put your suggestion to the gnome team in charge of Rhythmbox directly. This can be done by following the instructions here http://www.gnome.org/projects/rhythmbox/feedback.html If you use Gnome Bugzilla to report your bug then please tag it to this one so we can follow it's progress. Thank you for your report. -- [Edgy] Can't open audio files with rhythmbox https://launchpad.net/bugs/79474 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs