Level 6 gestalt. Sources are very generous. The character is pretty much locked to chaotic/evil, and I intend to really min/max my Perform skill as a part of the character.
I'm considering a Beguiler (which I'd like to get converted to charisma-based, pending rather likely DM approval), with something else on the other side, tentatively either Warlock or Bard. Also, I intend to go with abyssal heritor feats (using as many flaws as I can possibly convince the DM to allow), including Otherworldly Countenance: Beauty, and try to get an extremely high Perform skill.
However, the question becomes, what uses are there for a high Perform skill at that level? Money, of course, though not much. Most Bardic Music doesn't really count; it's just an X-rank minimum to use various abilities, and higher scores mean little. Fascinate, however, does, more or less, as its DC is based on the Perform check result (though even with a mediocre Perform skill, the DC already ends up almost arbitrarily high). I know of Melodic Casting, which lets Perform replace Concentration. Sublime Chord and Exemplar have uses, though I'm not particularly interested in either and they're out of reach at level 6.
Race is undetermined, though there is demonic heritage in there. Classes are only vaguely sketched out, though I will be charisma-based. Feats are in harsh demand, depending on how many flaws are ultimately allowed, with strong emphasis on abyssal heritor feats.
Any other suggestions?