I am working on a (somewhat) functional version of the classic Bard/Barbarian hybrid. The lynchpin is using Rage Casting(Dragon #310), which requires casting to be a free action, citing Quicken Spell(PHB) as a potential option. To do this I'm using Metamagic Song(RoS) to power a quickened spell and using Rapid Metamagic(CM) to make this acceptable for spontaneous spellcasting, and other means of reducing metamagic cost in order make it cost less. Consequently, I need to have as many uses of Bardic Music per day..

What are the most inexpensive and efficient sources of extra uses of bardic music? Ideally I would like it to be at least 60-70.

Character is a Bard 5/Barbarian 5/Bard 10, he will have the expected gp of a 20th level character flaws are allowed, and feats can be used but are a premium due to already used feats above. Sources are official only, including Dragon Magazine.