AUSTIN, TEXAS

You know you're at the South by Southwest Music Conference when:

• One of the biggest rock bands of the past decade shows up unannounced to play at a barbecue restaurant, and the line outside stretches longer than at the opening of a Texas gun show.

• The hottest young band in the U.K. media makes its debut midday on the grounds of a Texas Baptist church, with the oft-demonized AOL as its sponsor.

• Two Minnesota bands play back-to-back to an elbow-rubbing crowd at party thrown by national music magazine Paste.

All that and many less momentous (but still enjoyable) performances happened over the first 24 hours of Austin's 25th annual mega-sized music fest. South by Southwest brings thousands of bands to a hundred or so clubs around downtown Austin, which are flooded with 100,000-plus attendees soaking up the 80-degree weather. A sign of its continued growth, the conference expanded to a fifth night with its first-ever Tuesday night showcases. Talk about starting off with a bang: The Foo Fighters took flight at Stubb's BBQ with only a few hours notice. Those who got through the three-block line were treated to a preview of the band's upcoming album, "Wasting Light." Those who didn't still caught ecstatically received sets by such names as Montreal's fuzz-rock band No Joy and Austin's own R&B-spiked rockers Black Joe Lewis & the Honeybears.

One of the most ballyhooed/pooh-poohed bands of this year's fest, British rockers the Vaccines wasted no time showing what they're worth outside First Baptist Church of Austin. The Vaccines displayed a cocky flair of Killers-esque pop/rock.

Minnesota's contingent of SXSW performers -- greater in number than ever before, with 36 officially accepted acts -- also got an early start on the festivities. The Doomtree hip-hop crew landed its own all-night showcase Wednesday night on Sixth Street. Both Trampled by Turtles and Jeremy Messersmith played at the Paste party.

Follow him on Twitter: @ChrisRstrib