Well to be honest I'm pretty unfamiliar with Bard (and Bard AI in general) so bear with me :p
My line of thought was, maybe during a raid a player would like to have, depending on botgroup compositions, Bards playing different sets of songs (ie: a melee-heavy group would get melee buffs, a caster-heavy group would get mana regen songs, a magic-heavy encounter may require heavy elemental resistances etc).
Unless this kind of reasoning already exists? As I said I'm still pretty much ignorant in that area. If this is the case you can pretty much ignore this