SXSW Brothers and Sisters: Dave & Phil Alvin, and The Haden Triplets

Dave & Phil Alvin at The Dogwood.

I didn't plan it that way, but my early Wednesday evening at SXSW turned out to be a tour de force of back-to-back brother and sister acts.

First stop was the tail end of the Guitartown/Conqueroo Kickoff party at The Dogwood, where I first caught a quick two songs of country outlaw legend Billy Joe Shaver, still going strong at 74.

Up next was the main attraction, brothers Phil and Dave Alvin, the frequently conflicting siblings who teamed up to front the great American vernacular music band The Blasters in the 1980s before having enough of each other.

The duo are back in action with Common Ground, a tribute album to blues titan Big Bill Broonzy which is due out June 3. ""We still squabble," Dave said, "But the one thing we don't squabble about is Big Bill Broonzy."

These days, the brothers rib each other good naturedly. When Phil forgot what the second song was going to be, Dave said: "I thought our brotherly common ground was so great that you'd telepathically know what we we were going to play next. Or that you'd remember what I told you backstage five minutes ago."

It wouldn't be right to say the the Alvins showed themselves to have not missed a beat with their first performance since making their first album together in 30 years. Vocally, they sounded better than ever.

Back in the day, Phil was a fabulous blues and rockabilly singer and Dave a sterling songwriter and sting guitarist. That's all still true, but since then Dave has come into his own as a vocalist, and backed by a full band at The Dogwood they traded lead vocals on both Big Bill songs from the album and the very funny Dave song about the one question you're most tired of answering: "What's Up With Your Brother?" And yes, Blasters fans, they did play "Marie, Marie."

From there, after a break for a pulled pork sandwich, it was on to the sanctuary at St. David's Church for The Haden Triplets. Petra, Tonya and Rachel Haden are the daughters of jazz bassist Charlie Haden. Petra is the best known - she fronted '90s alt-rock outfit that dog., and has recorded a pair of technically dazzling solo albums, in which she reimagined The Who Sell Out and theme music from classic American films - last year's Petra Goes To The Movies - with her voice substituting for almost all of the instruments.

All three Haden sisters are remarkable singers, and as a trio the sisters have recorded a self-titled  album's worth of old time country and bluegrass laments that was produced by their father's good friend Ry Cooder. It's out on Jack White's Third Man Records label.

At the  impeccable sounding church sanctuary, Petra played occasional violin and the sisters sang in unison on songs by Bill Monroe, and the Delmore and Louvin Brothers that would fit the mood that would overtake Austin with the tragedy that woud occur blocks away later in the evening.

The harmonies were pristin and almost eerily perfect in  Sometimes you wish one sister would assert herself over the others to put a personal stamp on a song. Petra did that on a powerful version of the Carter Family's "Will You Remember Me," and the trio took it home with a breathtakingly beautiful take  on The Everly Brothers' "So Sad (Too Watch Good Love Go Bad)."

Previously: Synth-pop catharsis with Future Islands Follow In The Mix on Twitter