In 1998, Neutral Milk Hotel released an album of hallucinatory folk-rock called In the Aeroplane Over the Sea that is, it can be said without fear of exaggeration, nothing short of a heartbreaking work of staggering genius. Like My Bloody Valentine's Loveless, it is lightning caught in a bottle, one of those rare perfect albums that come along maybe once a decade.

Or once a lifetime.

In 1999, Jeff Mangum - Neutral Milk's singer, songwriter, and primary guitarist - disappeared from public life without explanation, declining all entreaties to perform or discuss the album or record a follow-up. Over the course of his decade-long Salinger-like hermitage, succeeding generations have discovered and come to revere the album, and as such it has become something like The Catcher in the Rye of indie-rock.

Two years ago he emerged from seclusion and started performing again, refusing to offer any explanation for his mysterious disappearance or sudden return. No matter. The ambiguity only seems to heighten the intrigue of his legend. Wednesday night's performance at the Irvine Auditorium, at Penn, sold out in 35 seconds.

Taking the stage dressed in a white cranberry-checked cowboy shirt and a droopy gray Mao cap, the 41-year-old Louisiana-born Mangum waved hello, took a seat, strapped on an acoustic guitar and tore into the slashing, Who-like opening chords of "Two-Headed Boy," blaring the agony and ecstasy of the lyric with his trademark, heart-tugging yelp like it was 1998 all over again.

Although the passing years may have shaved off a high note or two from his range, his sheer lung power and anthemic strumming formed a powerful twin engine of raw beauty and naked emotion.

For the next hour, he ran down the bulk of Aeroplane's bruised majesty with sporadic detours into rough gems from its predecessor, 1996's On Avery Island, and "Little Birds," the only known post-Aeroplane song he's written. Occasionally he was backed by trumpet or singing saw from former Neutral Milk sideman Julian Koster, whose current band, the Music Tapes, opened the show with a whimsical set of wistful post-rock circus music.

For the first third of the performance, the audience sat in hushed reverence, which was a little too quiet for Mangum's liking. "You guys can yell things at me, you don't have to be polite," he said at one point. From then on, the end of songs were punctuated with shout-outs from the audience. "You're an angel!" "You made me love music!" Mangum said that these songs were like "messages in a bottle" and he is deeply moved by how far and wide they have circulated and how beloved they have become. Amen, brother. Long live the King of Carrot Flowers.