Augument Familiar (SpC), for a combat familiar, sounds like a perfect thing to make your familiar concentrate on for Shared Persistant Sonorous Hum...
Drums of War (Heroes of Battle, Bard 4) is kind of nice. -2 to hit and saving throw, no save, FOR EVERY ENEMY IN MEDIUM RANGE. That's a large area to cover...
Enrage Animal looks decent also. Have your party AC enraged 24 hours...
Makes the Joyful Noise (SpC) useful, I think
Hm, can have the whole party Raging (As par Rage Spell) 24 hours if you want, I think.
Ahhh, you can move Rainbow Pattern! I bet you can do funny things with it...
Share Husk *could* be used if Chain of Eyes didn't exist...
Ohhhh, Summon Swarms. If only we can control Swarms!
Unfortunately, the Sonorous Hum has the clasue "Next spell you cast that requires concentration to maintain" and "maintained spell expires as normally would", so we can control one casting of Manyjaws or Telekinesis to control with one casting of the Sonorous Hum, but they expire after short while (1 round/CL for telekinessi, 3 rounds for Manyjows) and next concentration-based spell doesn't get maintained by the Sonorous hum anymore. Alas, it'd be cool if Telekinesis was 24-hour deal...
Elemental Monolith, Alas, is also 1 round/CL...was hoping for 24-hour pet!
-K