"I wish I wrote this next one. I wish I wrote them all, to be honest," said Matt Shultz of Cage the Elephant, after finishing an anxious "Breakdown" with Matthan Minster. Both shared the stage, singing and shouting "It’s alright!" with appropriate pain and attitude. Shultz didn’t leap into the crowd, but turned the energy way up on "American Girl," leaning over the crowd, finger high in the air as he shouted of a girl "raised on promises," singing like the words were his own.

Jonathan Bates of Big Black Delta isn’t a flashy dude, but Petty’s "You Got Lucky" inspired the singer to rock some disco dance moves at centerstage. Bearded and wiry behind the mic, Bates dug into Petty’s 1982 hit single with bite and warmth, with Dhani Harrison on electric guitar and Scaggs plucking a deep bass groove. Later in the night, the Pierces had some fine sisterly choreography, but when Bates stepped back during an instrumental break on "You Got Lucky" to really get down, shuffling and spinning in place, Petty Fest reached its boogie-happy peak.

"You want to sing along? You guys were probably already singing along," said Emily Armstrong of Dead Sara to the crowd mid-way into the night. At February’s Fleetwood Mac Fest, Armstrong nearly stole the show from several better-known vocalists with her tough, fiery reading of Stevie Nicks’ "Edge of Seventeen." The singer had the same effect Tuesday on Petty’s "Here Comes My Girl," raging through the lyrics, then easing to a vulnerable purr on the chorus: "Here comes my girl/Yeah, and she looks so right/She is all I need tonight." She sang and shouted and anxiously paced the stage, delivering with real passion. Couldn’t she have stayed for another song or two?

Actor Danny Masterson was one of the night’s most recognizable faces at the Fonda, but (as he did at February’s Fleetwood Mac Fest) the That '70s Show star spent his onstage moments happily strumming an acoustic while leaving the spotlight to a worthy singer: Adam Busch. Accompanied by the jangle of mandolin and guitar, Busch ripped right into "Yer So Bad" (from Petty’s 1989 solo album Full Moon Fever), savoring one of Petty’s most biting and hilarious lyrics: "My sister got lucky, married a yuppie/Took him for all he was worth/Now she's a swinger dating a singer/I can't decide which is worse."

Tom Petty has a special relationship with Los Angeles band the Shelters. He co-produced their self-titled debut album this year, then took the quartet on the road with Mudcrutch. They returned the favor at the Fonda with a tough reading of "Listen to Her Heart," with singer-guitarists Chase Simpson and Josh Jove harmonizing while strumming and plucking their electric guitars. With slick hair and a big Rickenbacker guitar, Jove then erupted with an explosive flurry of notes that was true to the Mike Campbell's original while sounding urgent and new. After their appearance, Scaggs noted to the crowd: "Tom Petty must know what he’s talking about."

Dhani Harrison is a regular at the Best Fests, including 2014’s George Fest, a tribute to his father, George Harrison. He arrives guitar in hand and ready to rock for whichever artist is being rightfully worshiped, and this time took the lead on Petty’s cosmic "Don’t Come Around Here No More." The tune was catchy and upbeat, with four additional background singers recruited at centerstage, leading the crowd though playful shouts of "Hey!" But as on the original 1985 hit recording, the song’s most supercharged moment came at the very end, with overlapping wah-wah guitars conjuring up a psychedelic freakout that ended way too soon.

Among the night’s many interpretations of Tom Petty and the Heartbreakers, there was one voice that best captured the sound of the man himself: Cory Chisel. Performing 1994’s "It’s Good to Be King," the Wisconsin-based Americana singer stood at the mic bearded and covered in denim as he fully recreated Petty’s relaxed snarl and defiant attitude.  He did it again at the end of the night, taking Petty’s parts on the Traveling Wilburys tune "End of the Line," as Harrison stepped in for his dad's lines.

Incubus frontman Brandon Boyd arrived late in the show to lead the flinty rock ballad "Mary Jane’s Last Dance," a Top 20 hit in 1993. With long hair past his shoulders, Boyd gave a forceful reading as the band ripped up on guitars. Boyd hardly moved onstage, seeming to command the room with hardly any effort. Though he only performed one song, Boyd showed the crowd how to deliver a big rock song with both force and ease.

Jakob Dylan began his two-song appearance at Petty Fest with a corny wisecrack: "If you know this song, it’s worth waiting for." But the crowd would have to wait a little longer, when Dylan soon stopped the song after one of the band’s guitar amps failed. After a few moments killing time as the amp was replaced, Dylan and the band dove back into the Petty classic with extra urgency. They followed with "Rebels," from Petty’s Southern Accents album, which Dylan said might be his favorite, delivered with a helping of fire and regret.

Comic actors have appeared on the Best Fest stage before (Will Forte sang at Fleetwood Mac Fest), but Kristen Wiig’s appearance beside Norah Jones for two songs added some welcome warmth to biting lyrics like "And turn the radio loud, I'm too alone to be proud." Wiig waved to friends in the crowd and sang harmonies with Jones on "You Don’t Know How It Feels" and "Time to Move On" without pretension, and sometimes with a shy grin that suggested she was as happy to just be part of the night as anyone in the audience.