South By Southwest. St. Patrick’s Day. Sixth Street. What could possibly go wrong?

The first full day of the South by Southwest (SXSW) Music Conference coincided with St. Patrick’s Day this year. Navigating central Austin during SXSW is difficult under any circumstances, and the added excitement of having to dodge hordes of green-clad revelers only adds to the challenge. But once inside the sampling of showcases I attended, the focus was mainly on the music, not the green beer. And, thankfully, history did not repeat itself in the form of a police arrest.

It was six years ago to the day (give or take a couple of hours) on Sixth Street when LA’s Grammy-Award-winning band Ozomatli ran afoul of the Austin Police Department at the end of their set on the opening night of SXSW. The showcase ran late, the band went on around 1:30, and when they finished with their then-standard closing (leading the crowd in a chant, moving them in a conga line out the door for a brief jam, then returning inside to say goodnight), police, concerned that the music and activity “could incite a riot,” demanded the band stop playing and return inside the club. Accounts differ widely about what happened next, but when the smoke cleared, two band members and their manager had been arrested and charged – two with misdemeanors, and one with a felony.

Six years later, all the legal issues have been resolved, and the members of Ozomatli returned to SXSW and Sixth Street to bring their blend of hip hop and salsa, cumbia, samba and funk, merengue and comparsa, East LA R&B and New Orleans second line, and Jamaican ragga and Indian raga-fusion to a receptive audience. Their new album “Fire Away” drops on April 20 (or 4/20 - Coincidence? I think not!)

From the first notes of their opening song, “Malagasy Shock”, Ozomatli energized the crowd and turned the Galaxy Backyard tent into a dance floor. (Under an upbeat tone, this new song refers to an actual incident in which singer Raul Pacheco was electrocuted on stage in front of thousands of people on a State Department trip to Madagascar.) Other songs from the new album included “45” and “Gay Vatos in Love.” (Of the latter, Pacheco says “We say, let every person have the right to choose who and how they love one another.”) Ozo also added popular favorites such as “City of Angels” to the mix.

As the set drew to a close, the band launched into a high-energy version of “Como Ves”, and just as momentum was building, the band’s vocal mics suddenly and inexplicably went dead. This might have deterred a lesser band, but Ozomatli simply took their instruments into the crowd, and began a revved-up instrumental jam/drum circle to conclude the evening. There would be no parade out onto Sixth Street this night, and no arrests – just a high-octane show that left the crowd wanting more from the LA band.

(Houston audiences can experience Ozomatli for themselves on April 17, when the band headlines the Bud Light World Stage at the Houston International Festival.)

Immediately preceding Ozomatli was London’s Fanfarlo, led by Swedish songwriter Simon Balthazar. Anticipation was high for their appearance, and badge-holders turned out in full force, filling the Galaxy Backyard tent to an uncomfortably full capacity. The group employs an array of instruments ranging from keyboards and mandolin to horns to create their indie folk-pop sound, and their performance did not disappoint the packed house.

Later in the evening over at La Zona Rosa, Houston rappers Chamillionaire and Paul Wall kicked off their highly anticipated reunion tour.

Wall and Chamillionaire, friends since they were five years old, released their first, critically acclaimed album, Get Your Mind Correct, in 2002. But a year later, a personal “beef” separated the two, threatening the momentum of the Southern rap community to re-establish a Texas identity in the rap genre. The two reportedly reconciled at the urging of the late rapper Pimp C, who encouraged them to come together for the sake of the Texas movement.

The two energized the crowd with highlights such as Wall’s Grammy-Award-winning single “Ridin’,” and Chamillionaire’s new single “Main Event,” released last month to coincide with the 2010 NBA All-Star Game in Dallas. The hour-plus La Zona Rosa show ended with a brief reference to the duo’s past “beefs,” but it was clear that reconciliation was in the air.

(Paul Wall and Chamillionaire will bring their “In Love With My Money” tour to the House of Blues in Houston on April 23.)