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FFG's Path of Magic has some very nice alternatives to the bardic singing (ranged whilwind attack anyone? How's about giving flanking bonuses against all enemies withon 15 feet...). These also add additional abilities for buffing or dampening other spellcasters. The choir can make for a damned impressive ritual. You become a walking metamagic feat.
The source allows you to take feats to gain them. I have them choose them at levels 1st, 5th, 10th, and 15th.
Complete Book of Eldritch Might - a Malhavo Press (Monte Cook) book, with a variant bard in it. I use both it and the PHB, as mentioned in my post above.