Namely, can two different groups of people be designated as allies for the purpose of the effects?
In other words, can I pull of the Icy Heart Bard (my name for the combo that puts Explosive Spell on Inspire Courage) on one group of people, while affecting a different group with Dragonfire Inspiration?
Because if so, I will feel the necessity to build this character. Possibly with a Pact Primordial to get the slots for an Innate Spell (Explosive Born of the 3 Thunders Sonic Substituted Flash Frost Snowcasted Inspirational Boost).
Thanks to the Pact Primordial netting you a single slot of any level you want...
Would require a shitload of feats. Ah well, I can retrain all of that metamagic to useful stuff after I Innate the spell.
Hmm...
A Silverbrow Human Eberron Bard with 2 flaws (and no morals), could nab all of the above at 6th level, including the Innate Spell, and still have Dragonfire Inspiration (replace countersong with it, seriously); with the right instrument, that is up at +3d6 cold? damage for my allies. and with feat retraining, I can knock that up to 4d6 at 7th, nab a Helm of Opposite Alignment, and grab Words of Creation at 8th (retraining again), so that I can finally get it up to a respectable +7d6 cold? damage.
And anyone who annoys me gets pasted against a wall somewhere out of earshot. And I'll yell that part of the song.