“I’m not really an opera,” says dynamic performer Joseph Keckler at the start of his tantalizing song cycle–cum–multimedia one-man show I am an Opera. “I just said that to intrigue you.” Joseph, you tease! If not nearly as overblown as an opera, he certainly exemplifies what would happen if you took Julian Casablancas and gave him Rufus Wainwright’s opera jones and piano chops, a striking basso profundo, and Adrien Brody’s fantastic nose. This charismatic mop-top delivers an off-handed, clever mise en scène combining Laurie Anderson and Nature Theater of Oklahoma technique: While interacting with giant video projections and supertitles, Keckler sings, in three languages, a classical pastiche whose text describes a (possibly autobiographical) bad trip on shrooms in familiar colloquial jargon: “I was re-becoming a teen goth.” He’s most successful when he exploits his Warholian deadpan; the tension between the bombast of his singing and the inconsequence of his tale create a high percentage of what’s charming about the piece. The man himself handles the rest, with magnetism and poise so high that he seems (like Wainwright) to have been born onstage. By singing a finale cloning Antony & the Johnsons, though, he makes it clear that earnest isn’t his best mood, his falsetto’s less fun than his bass, and that rock ballads don’t suit him as well as cheeky arias. Somehow it all works as long as he follows the Lieder.