South by Southwest features the Boss, Alabama Shakes, and a Philadelphia flavor

AUSTIN, Texas - The 2012 South by Southwest Music Festival officially got under way Wednesday, with day parties all along the Texas state capital's Sixth Street strip and official showcases for up-and-coming and already-arrived bands banging on at more than 100 venues.

There are more big names than ever this year in Austin - rap kingpin Jay-Z played a free show downtown on Monday before the festival began but while the SXSW film and interactive conferences, the latter a must-attend for tech and social-media geeks, were peaking.

The other big kahuna in town this year is Bruce Springsteen. He's set to sit in the SXSW keynote chair, previously inhabited by such other gray eminences as Neil Young, Quincy Jones, and Smokey Robinson, and give a talk Thursday morning. (Like many happenings in Austin this week, his speech, at noon EDT, will be streamed live. It will be at npr.org/music.)

After his speech, Springsteen will play Thursday night in an as-yet-unspecified "intimate venue" with the E Street Band, in advance of their tour, which comes to the Wells Fargo Center on March 28-29. In an unprecedented SXSW move, tickets for the Boss' Austin show are being awarded via raffle, to discourage 24-hour lines and scalping.

Philadelphia is represented in Austin in numbers. I did my best to start off SXSW right by checking out Santigold, the Mount Airy-raised stylish alt-pop act (whose sophomore release comes out in May), at the spacious club La Zona Rosa.

No such luck. Despite arriving early enough to see Brooklyn rapper Theophilus London - who went on before Santigold, born Santi White - and despite being on a supersecret, extra-special VIP list, I couldn't get in. In a sign that the 26th SXSW is going to be the most bonkers yet, the venue was so crowded that the fire marshal wouldn't let anybody else in.

Oh, well, there are a couple of other Santi shows: Wednesday at the Fader Fort, the pop-up hipster headquarters across I-35 in east Austin, and Saturday at the Spin magazine party at Stubb's. If at first you don't succeed . . . .

But as I was saying: There are lots of Philly acts down here. The War on Drugs, which had a big 2011 with their album Slave Ambient, are out to expand their audience with a handful of high-profile shows. Hip-pop duo Chiddy Bang are playing all over town in support of their new album, Breakfast. Singer-songwriter Adam Arcuragi, pop-rock band Free Energy, neo-gangsta rapper Meek Mill, indie duo Bleeding Rainbow, heavy rockers Purling Hiss: They're all here.

There's also a one-stop-shopping SXSW stop on Thursday afternoon, sponsored by WXPN-FM's music blog, the Key, and Collingswood Web show Bands in the Backyard. It's free from noon to 6 p.m. Thursday at 913 W. Johanna St., if you happen to be in Austin, and features Attia Taylor, Oh! Pears, Break It Up, and some non-Philly bands.

What else is going on? Everything, it seems. There are cool-sounding movie screenings to try to get to: Bad Brains: Band in D.C., about Rasta-thrash legends Bad Brains, and Searching for Sugar Man, about late '60s Detroit musical mystery man Rodriguez.

There's alt-hip-hop at SXSW, as there has been for years. I'm glad I didn't try to see the smart-mouthed emcee Kendrick Lamar on Tuesday - he missed his plane and the gig. There's also more mainstream rap than ever before. Lil Wayne, 50 Cent, and Nas are all playing, the latter on a bill Saturday that includes the high-volume noise-pop duo Sleigh Bells.

Amid all this music, people will find time to talk about music - often just when they should be shutting up and listening to it. There are a host of panels about streaming services, the iCloud, and what the future of the music business is, if indeed there is one. One of those panels is called Downloaded, after a forthcoming documentary of that name, about the transformation of the biz since the advent of Napster in 1999. I'm headed there now.

This week's first SXSW revelation, for me: The Alabama Shakes are really good. I suspected as much based on "Hold On," the terrific soul-burning single by the Athens, Ala., fivesome that grabbed the attention of cool-hunters late last year.

But I wasn't quite sure about the band, which is led by 23-year-old Brittany Howard. A belter, she's got a staccato vocal attack that's more reminiscent of Otis Redding than Janis Joplin. That's partly because they haven't put out much music, just a four-song self-titled EP in advance of their debut album, Boys & Girls, which comes out on Dave Matthews' ATO Records label on April 6.

I must admit I had creeping doubts, as well, due in part to a bit of an Alabama Shakes backlash already going on. This is the way things get chewed up and spit out in the 24/7 media marketplace. A young band just getting their legs under them puts out a great single ("Hold On"), and first everybody from Patterson Hood of the Drive-By Truckers to Rolling Stone is raving about them, and next thing you know they've got a song in a TV commercial for Zales diamonds.

But along with the hype comes the suspicion that this young band is already too big for its britches, and maybe it doesn't deserve to be taping an episode of Austin City Limits (which it did Tuesday) before its first album even comes out.

So for bands like the Alabama Shakes, who will play Philadelphia's World Cafe Live on April 9, SXSW turns into a proving ground. The crowd of a thousand or so who watched them rip through a 13-song set Tuesday weren't familiar with most of what they were hearing, but by the end of the show were responding as if they knew them deep down in their bones.

With a Hammond organ fill here and punched-up drums there, the Shakes work with familiar soul-rock tropes. But Howard is something special, wailing away on "Always Alright" or hopping around the stage with guitar in hand on the noveltyish "Making Me Itch."

The band also made its case where it counts, with tender, self-knowing songs such as "Boys & Girls" and "I Ain't the Same." While Howard is a belter alright, she impressively deployed a delicate upper register, showing that when she wants you to listen she doesn't have to shout: She can command your attention with a whisper.