I'm at work and can't open DM here, but it probably says something like "sync media" or "manage songs, ringtones, pics and video" or something along those lines.
I think that media manager is new in 4.3 and higher. Blackberry teamed up with rixio for the software. Download the latest DM and you should have the music option
Posted from my CrackBerry at wapforums.crackberry.com