So it was a band singing in a language that wasn't English, with a name that started with a letter of the alpabet? Hmmm...
Seriously, if you hear it again then if you are ingame you can type /tell gridbot playing to get the name of the song playing - and more usefully if you just miss it then you can also type /tell gridbot history to get a list of the previous 10 songs played.
And if you hear it and you're not in game, then not only is the current song listed at the top of the forums and on the main homepage on here, but there's also a list of recently played songs here:
http://www.gridstream.org/gsp-nextgen/s ... story.aspx
So hopefully if it gets played again then you can track it down.
If you think of any more details in the meantime then post them here cos I'm quite intrigued now aso to what it was... so please let us know if you do work it out!