3:30 p.m. Still they file in.

Watching the crowds trudge along Barton Springs Road, their eyes fixed on the pavement about five yards in front of them (not their phones), always reminds Rocks Off of a pilgrimage. And each festival has its "saints," musical altars where the performers gather to pay homage.

This year, so far, it's two British acts who aren't here, but whose presence permeates the festival's early hours, the artists responsible for two of the most resilient (and successful) records of the past 12 months: Mumford & Sons and Adele. Folk-rock is back in a big way, as are female singers whose sheer vitality prevents them from being labeled outright throwbacks.

With no agenda or strong opinions about anyone on the field this afternoon, Rocks Off set out on our first ACL afternoon cruise. Our first stop was a brief rondezvous with Ha Ha Tonka, Ryan Adams bash & pop with a New Wave pulse and needlenose mandolin. Jangly!

Then it was the Secret Sisters, more like the Everly Sisters. The Alabama siblings voices were more harmonious than their offstage behavior. The non-guitar-playing sister assured the crowd "we fight like cats and dogs." Songs of devotion and doubt, and an admirable grasp of country music history: Hank Williams' "Your Cheatin' Heart," Patsy Cline's "If You've Got Leavin' On Your Mind" and Skeeter Davis' "Am I That Easy To Forget."

Haunted gospel and an ode to "mean old Southern boys" (and the women who fall for them) in the Sisters' own "Tennessee Me." They indulged in some "Willie-baiting" - a popular activity in Central Texas, where mentioning Willie's name guarantees a pop from the crowd - before backing it up with "Blue Eyes Crying In the Rain."

Brandi Carlisle put some spine and strum into what the Secret Sisters were going for. Her fiddler, who should be playing on a hickory stump somewhere, helped. A song called "Dreams" was not a cover of the Cranberries' 1993 hit, just a close cousin. "Closer to You" had an Indigo tint, and "What can I Say" touched on the folk songs of the Cranberries' grandparents.

Carlisle and her band pulled out all the rockabilly stops during a pistol-packin' cover of Johnny Cash's "Folsom Prison Blues," but her band traded too many solos - known in festival-speak as "filling time" - so we wandered over to the Austin Ventures stage.

We walked up on Fool's Gold, the oddest (and coolest) group we saw this afternoon. They were in the middle of "Nadine," which paired a hypnotic ragga rhythm with a tenor sax that almost had some bagpipe in it. The rest of the set was a sun-splashed blend of Afropop and calypso that reminded us of listening to Paul Simon's Graceland at Leon's Lounge a few days ago, so we wandered off.

About the past two or three times Delta Spirit have passed through Houston (they liked Walter's a lot), some friends have urged us to go. Now we know why. Noting they were the only rock and roll band on a stage soon to be dominated by Big Boi, Nas & Damien Marley and some guy named Kanye, they did prove once again that any band that packs an extra drummer is destined for festival success.

But Rocks Off was more impressed with their free-flowing songs, with patches of harmonica, organ, piano not that many chord changes, fast Buddy Holly beats (those drummers deserve an extra meal voucher), Morse-code guitar and one odd minor-key melody that caused us to write "Dan Fogelberg" in our notebook for the first and perhaps only time.

That's the kind of "indie-rock" we like. It was folky in its own way, or at least wholesome - the singer dedicated a song to his mom and his new wife.

Briefly, we also stumbled across another ACL saint of 2011, the electronic palliative we believe the kids refer to as "chillwave. It was the end of Wild Beasts' set, and we only caught one song, true, but the pillowy keyboards reminded us of Arcade Fire without all the crazy drum action. It's not bad... it's just not especially interesting, either.

Even though it rained, the smoking ban seems to be holding. We've only seen a few scofflaws, and only smelled weed a few times. It's early.

Keep an eye on Facebook and Twitter for more. Rocks Off isn't going anywhere.

Overheard at ACL: "It's like, you are really in knee-high suede boots..."

Also: "We might have to download this one."

Random Notebook Dump: Our favorite line from the ACL media guidelines email: "Live-tweeting and Facebook updates do not count as coverage."