AUSTIN, TX—Sharing a place on the short list of rock’s very best “dark night of the soul” masterpieces—right up there with Neil Young’s Tonight’s the Night and the third album by the Velvet Underground—Big Star Third (a.k.a. Sister Lovers, recorded in 1974 but released in the sketchiest of ways in 1978) is by far the most complex and emotionally turbulent music that the influential cult heroes from Memphis ever crafted.

It also is the most timeless, ultimately the most rewarding and arguably the best way to pay tribute to Big Star’s legacy and long-ranging influence.

As much of the assembled music media shuffled off to catch an invite-only showcase by Bruce Springsteen on Thursday night, what seemed like all of the rest filled the Paramount Theatre for part two of the Irish wake spontaneously held during SXSW 2010 when Alex Chilton’s sudden death derailed a scheduled Big Star reunion show.

The evening started with some crossover to the film festival and a work-in-progress screening of Big Star: Nothing Can Hurt Me, a new documentary by Drew DeNicola. The director and producers emphasized that they did not want reviews of the film, since it is not yet completed, and it does need to be trimmed in a few spots and briefly fleshed-out in others. But surely they won’t object to a one-sentence reaction.

The movie is brilliant—a boon to Big Star fans, as well as an indispensible primer for anyone who ever has wondered what artists such as the dB’s, R.E.M., Matthew Sweet, the Bangles, the Replacements, Teenage Fanclub, This Mortal Coil, the Posies and literally thousands of others found so inspiring.

The second half of Big Star Tribute Night was just as fulfilling as the band’s last surviving member, drummer Jody Stephens, and long-time fans Chris Stamey and Mitch Easter led a large ensemble complete with Mellotron, horns, string section and a parade of guest vocalists through a rendition of Big Star Third/Sister Lovers in all of its soul-wrenching sloppiness and haphazard perfection.

The procession of cameos included some big names—R.E.M.’s Peter Buck, the Replacements’ Tommy Stinson, Wilco’s Pat Sansone, M. Ward and of course Posies and latter-day Big Star members Ken Stringfellow and Jon Auer—but just as valuable were the contributions of many younger and lesser-known musicians who’ve passed through Stamey’s recording studio in Chapel Hill, N.C. All of them clearly loved the album and poured all they had into songs beloved by fans who never thought they’d get to hear them live: the rousing “O, Dana” and the despondent “Holocaust,” the frightening “Kangaroo” and the furious “Kizza Me,” all building up to a “We Are the World” sing-along on the perfect tune to stand as the band’s epitaph, “Thank You Friends.”

Various combinations of the musicians then returned for a shorter mini-set of songs from Big Star’s first two records and the solo work of founder Chris Bell, but the transcendent “Thank You Friends” was a tune that couldn’t be topped.

The second big draw of the night for this blogger was a set by Cardinal,another cult-favorite band that has proven to be nearly as revered and influential to a different generation of fans. Its (until recently) sole self-titled album in 1994, a collaboration between Australian psychedelic-folk singer and songwriter Richard Davies and American trumpeter and arranger Eric Matthews, started a revival in orchestral pop that inspired the Flaming Lips, the Polyphonic Spree and many other bands, culminating with the impressive success of the Arcade Fire.

Alienated for quite some time, Davies and Matthews reunited for a new album, “Hymns” (Fire Records), released in January; “We didn’t rush the second album,” Davies joked onstage at Beale Street Tavern. But Matthews shuns live performance, and the version of Cardinal that performed songs from that first album and the new disc at that tiny venue consisted of Davies, three backing musicians and, sadly, no trumpet or any of the other orchestral instruments that make Cardinal an undeniable classic.

Yes, it was fun to hear those songs live, even in ramshackle garage-rock versions. But one couldn’t help wondering how magical the experience could have been in a setting like the Paramount Theatre and with the orchestral backing that Stamey brought to the Big Star project.