I suppose the hard part with the undead stuff is effectively always being one level behind where I should be...
Eh, there's not really much to say. Human* Powerbard first (because the bonus feat is more useful for the base than the ghost. >_>; ), then Ghost on top, using the ACF that gives me a Caster/Initiator/Manifester/etc. level to catch up.
Inside the Winter Storm
Rhythm, Dragonforce 1
Area: 60-foot radius emanation centered on you
Duration: 1 round/level
Saving Throw: Will negates (harmless)
Spell Resistance: Yes (harmless)
Your allies' weapons acquire a coating of frost, creaking with sudden cold.
All allies within the area deal an additional +2d6 cold damage with every attack for the duration of the chord.
Remember the Trashcan
Rhythm, Wyld Stallynz 1
Area: 60-foot radius burst centered on you
Duration: 1 minute or until discharged
Saving Throw: Will negates (harmless)
Spell Resistance: Yes (harmless)
Your allies suddenly feel luckier than usual.
All allies within range (including yourself) gain a luck bonus equal to your Charisma modifier on their next saving throw, as long as it occurs within 1 minute from when you played this chord.
Those two or three times a day each, telekinesis (1d4 rounds, CL = HD) and dimension door (myself and ghostly stuff only) from being a ghost, and some standard-action abilities that give lesser boosts. Thinking these three:
Presto Con Fuoco -- Allies within 30 feet deal +2 energy damage, gain energy resistance 3 for 1 round/level.
Vivace -- Allies within 30 feet gain 1d4 temporary hit points for 1 round/level.
Marcia -- Allies within 30 feet gain +5 foot morale bonus to land speed and the Run feat for 1 round/level.**
As for feats?
Musically Gifted (Cha counts as 2 higher where music is concerned), Up-Tempo [Chord] (can play the lesser things as a Swift action CHA Mod times a day), Subliminal Tune [Chord] (spend two uses to play music silently somehow).
*Because CHA-boosting races are rare and Lesser Aasimar would be weird.
**For running away.
The hardest part is working out what their skill list is like, since they get 6+ but SirP basically consolidated half of them, so it works out as twice that or more. @_@