For your bard:
Dragonfire Inspiration from Dragon Magic, sacrifice Inspire Courage bonus for party-wide d6 Sonic dmg on attacks per +1 it would normally grant
Masterwork Lyre should add +1, ramping it up to 2d6
Inspiration Boost bard spell from Spell Compendium for another d6
(If you can go good-aligned, take Words of Creation from Book of Exalted deeds to take nonlethal dmg and double inspire courage bonus, ramping it up to 6d6)
Then, use your Pipes of Pain affect (if you have time in combat) to double the sonic dmg with its curse, adding 6d6x2 (not 12d6, you roll then double the outcome) sonic dmg on each ally's attack.

Also considering Melodic Casting (Complete Mage) for casting spells while performing, Lingering Song (Complete Adventurer) or Harmonizing weapon for songs to continue after you stop performing so you can join in.

Consider Bow of Songs - use bardic music per-days to add your charisma to the bow's attack and damage, making great use of your high dex and charisma.

You could also grab Dragon Heritage (there's a feat to let non-sorcs do it) for the Sonic Breath attack from Races of the Dragon, so you can breath sonic damage in droves while performing your song.

Watch as your party's jaw drops at the massive damage boost you're putting out. Pray your DM doesn't pit you against enemies that are immune to sonic damage (rare though they are.)

Consider the Warchanter Prestige class if you're interested in melee combat, GREAT benefits, you'll never miss melee attacks again, and you'll grant your party max possible BAB for their level (based on the higher party member's BAB, so if you got a fighter/barb/ranger, SHIT IS ABOUT TO GO DOWN.)

If you need specifics, contact me, cus I know this is a lot to take in.