Young women in straw cowboy hats waved their arms in the air and swayed atop the shoulders of young men.

Gray-bearded Deadhead types in light blue denim shirts smiled and rocked gently on the heels of their worn cowboy boots. Couples danced in front of the stage. And surprise: the twenty-somethings in the crowd knew the words to all the songs and shouted them when prompted by the band to do so. Most of the songs were popular before they were even a gleam in their parents’ eyes.

Clearly, the band Petty Theft, a Novato-based tribute band to veteran rocker Tom Petty, has a cult following. They had turned out in force last weekend for Petty Theft’s appearance across the bay at Café Du Nord in San Francisco.

But will Petty Theft’s hardcore fans drive all the way out to Walnut Creek for the group’s gig at Dan’s Irish Sports Bar this Saturday night? One can only hope because a full house for a mellow rocking band like Petty Theft only makes a good show better.

Tom Petty’s voice always sounded kind of whiny to me. The somewhat slower pace of '70s countrified rock overall propelled me to seek out the faster harder picking of authentic bluegrass (interestingly, Petty Theft guitarist Monroe Grisman is the son of well-known bluegrass mandolin maestro David Grisman, who named his son for bluegrass great Bill Monroe). But a friend from Petaluma who prefers nostalgia rock over Kreayshawn wanted to meet up at the Café Du Nord show and it seemed like a good halfway point.

Nostalgia, it turns out, is music to the ears. After a slightly tepid ZZ Top cover band opening act, the six-member Petty Theft band came on the crowd and excitement was contagious. As the thumping chords amped up by the energy only live performances bring surged through the speakers ... suddenly, after all these years, hit songs like “Running Down a Dream,”  “Free Falling,” “Breakdown,” and “Won’t Back Down” sounded great.  Although the band’s musicianship is spot on, I know that these familiar melodies, once annoying to me, now triggered a deep nostalgia for my youth. And compared to pop hits like the jaded “Gucci Gucci,” a classic like “Even the Losers” seems fresh again.

But it’s just not me. And it’s just not Tom Petty. Tribute bands loom large right now. Very big. Even with audiences too young to wallow in nostalgia.

Name a mega band from the latter part of the 20^th century and there’s a cleverly titled tribute group making a living replicating their tunes. Led Zeppelin? There’s Zepperella, an all-female Zep tribute band, as well as Dread Zeppelin. Sting? There’s Stung. Aja vu is a wonderfully named Steely Dan band (a play on the term déjà vu and the popular Steely Dan album “Aja”). The Sun Kings are local favorites who play all Beatles all the time. Pretending is, yes, a local band pretending to be The Pretenders. And I just learned there’s an all-female Kinks tribute band called The Minks who play songs like “You Really Got Me” while dressed in period go-go boots and mini-skirts.

More than just covering the classic songs in their own style, tribute bands aim to ape the way the songs sound on the recordings we all know and love. That is what today’s audiences of all ages seem to want.

“Why pay big bucks to sit in some stadium to see some big rock star past his prime from so far away he’s the size of a toothpick when for much less money I can come hear these guys who have more energy and put on a better show in a smaller, better club space?” one young man commented. He was seated at the bar waiting for Petty Theft. Later that night he was bouncing to the beat at the front of the crowd.

Another young man, who had just seen a Smiths tribute band called Smiths, Indeed perform in Manhattan, observed, “Most current bands are just regurgitating lesser versions of what’s come before so people my age are tired of hearing new crappy things. We’d rather hear familiar great songs done well.”

As for me, I’ve outgrown my petty distaste of all tunes Tom. I’m going to head over to Dan’s to hear Petty Theft again on Saturday night. Even tribute bands get lucky sometimes.