Ubuntu One Music
Ubuntu One Music 1.0 for Mac is available as a free download on our software library. The application lies within Audio & Video Tools, more precisely General.
From the developer:
Ubuntu One Music streams your entire music library from your Ubuntu One personal cloud to your iPhone. Listen your music wherever you are or wherever you're going. Learn more about Ubuntu One at http://one.ubuntu.com.
You may want to check out more Mac applications, such as Electro Music Mixer, AirVibes - Online Music Radio or Music School - Pro Video Lessons, which might be related to Ubuntu One Music.