Bard 7 / Rogue 3 / Sublime Chord 2 / Arcane Trickster 8
That is my favourite "bard" build.
130+23xInt Skill Points (
Assuming you start as rogue, otherwise, -6.), 6d6 Sneak Attack, Casting as level 10 Sublime Chord and as 7th level bard (
Practiced Spellcaster and your with SubChord CL is 21, too. 25 with song of arcane power.. And well, all your other songs suck, so that's what you'll be using. Suggestion is DC 14+Cha, so you might use that situationally, though.). 6+11d6+8d4+20xCon HP (
Avg: 64.5+20xCon). Bardic Knowledge as level 9 bard. +5/+14/+15 saves, too. EDIT: And +12 BaB, with or without fractional BaB.
Or:
Bard 7 / Swordsage 2 / Marshal 1 / Sublime Chord 2 / Arcane Trickster 8
If your DM allows ToB. You get one bonus stance that can be handy, and some decent situational abilities. Oh, and wisdom to AC in light armor. In addition, the aura means that you WILL succeed on song of arcane power DC 30.
The best part? They are both rather viable on most levels. Just pick a bunch of support spells and sing stupid songs at low levels, trying to flank for sneak attacks if you can. Later on, well.. You have high level spells. From sorc/wizard spell list.