When it was time to anoint Harlem rapper A$AP Rocky as one of the big arrivals at this year’s annual South by Southwest music festival, fans threw their hands in the air. Then their drinks. Then two 40-gallon trash cans.

In a triumphant hail of garbage and spring water, the Saturday evening performance wasn’t just bratty, visceral fun. It felt like a thousand-odd fans subconsciously lashing out against 72 hours of sponsorship fatigue.

The corporate presence at this year’s SXSW felt oppressive, contaminating the festival’s hallowed musical ecosystem of sharing and discovery. Bemoaners have bemoaned that SXSW has slowly lost its soul over the course of 26 years, but this go-round was exponentially yuckier than last spring’s. Nearly every musical transaction felt sticky with Mountain Dew.

The city itself looked different. Each day at sundown, Red River Street transformed into a dystopian Usher video. Sponsors mounted laser canons on nightclub rooftops and blasted the skyline with jittery green spokes of light. Smoke machines vomited fog onto the sidewalk. Spandexed women in pickup truck beds chucked energy bars at pedestrians who weren’t hungry.

Some of SXSW’s biggest acts came to Texas only in the name of commerce. Lil Wayne was here to celebrate a Mountain Dew endorsement deal by performing an exclusive concert and releasing a new mixtape titled — not kidding — “DEWeezy.” The only thing more embarrassing would have been to give that concert on a five-story stage built to look like a giant Doritos vending machine . . . which Snoop Dogg did Thursday.

If companies want to keep their fangs lodged in America’s hipness jugular each March at SXSW, they will need to ease up on this stuff. The pact between artists and fans is sacred; the relationship between brands and consumers is not. If we all fly home from Texas able to name more flavors of Neuro energy drink than bands we fell in love with, meaninglessness wins.

Of course, there was still plenty of magic to be excavated in Austin this year: Piano man Robert Glasper delivered riveting techno-spiritual jazz; Los Angeles quartet Bleached tapped into rock-and-roll’s eternally scrappy charms; and U.K. producer SBTRKT rendered his mysterious dance tracks in arresting high-definition.

They were just three of more than 2,000 acts performing. Attendance and financial figures are still being tallied, but in 2011, SXSW added a record $167 million to the Austin economy.

This year, music penetrated the city’s every cranny. The Men, a buzzed-about Brooklyn rock troupe, could be found Friday afternoon thrashing away at a high-end bicycle shop. A Bianchi fixed gear hung from the ceiling like the Sword of Damocles.

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In the information age, artists no longer come to SXSW to create buzz onstage, they come to justify the buzz they’ve already generated online. Grimes, a Canadian micro-sensation whose music descends from Kate Bush through Bjork and spills out onto the 21st-century dance floor, had everything to prove at Clive Bar on Friday night. Bedraggled by a glitchy and feeble sound system, she howled in agony when the power gave out but soldiered on like a pro.

Fiona Apple, meanwhile, was one of many old pros hoping to bounce back into the vanguard at SXSW, but she sounded fidgety and freaked at Stubb’s Bar-B-Q on Wednesday. During new songs and old, she frequently replaced her plunging contralto with feral snarls. “You’re imaginary,” she told the audience at one point. “You’re not real.”

But we were real. And when the Shins launched their comeback ship on the public park grounds of Auditorium Shores on Thursday night, we were bored. With a new album out Tuesday, frontman James Mercer’s brand of yawn-rock ventured off into seas of melted vanilla previously uncharted.

SXSW career reboots rarely carry the same charge as new faces making new sounds, anyway. Performing inside a former office supply warehouse on Saturday, rookie New York duo Tanlines served taut pop-rock that was both bitter and sweet, assertive and comfortable, smart and sentimental.

They were followed by A$AP Rocky’s projectile-friendly set, which would have been a festival highlight had the 23-year-old not been up against the fleet of A-list rappers that had parachuted in for the week — Jay-Z, Eminem, 50 Cent, Kanye West and Rick Ross among them.

And that raises another red flag for SXSW: How can the someday-stars break out down here if the already-stars are hogging up all the chatter?

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In a just world, G-Side would have been the ones clogging our Twitter feeds on Friday. Flanked by two back-up singers, the Alabama rap duo staged a short, sweet, smooth tribute to the late Nate Dogg at Stubb’s — a moment of enviable nuance in the thick of SXSW’s chaos.

Other artists aimed to pluck attendees from the swirl of noise and advertising. Montreal’s Patrick Watson unspooled orchestral tunes in the serenity of St. David’s Episcopal Church downtown, while Oneohtrix Point Never — electronic musician Daniel Lopatin — forced listeners to reconnect with their eardrums by performing at the club Red 7 in complete darkness.

Cameron Stallones of Sun Araw had the same idea at the Mohawk late Saturday night. He asked the soundman to kill the lights before his trio playfully scrambled the DNA of dub reggae, Afro-pop and new age music. It felt imaginative, innovative, futuristic and full of life — exactly the kind of music you trek to SXSW praying you’ll wander into before it’s all over.

Then you do. And then it’s all over. Ashes to ashes, Dorito dust to Dorito dust.