The annual free three-day concert, one of the country’s biggest live music events, is expected to draw crowds of up to 750,000 people over the weekend with an eclectic lineup that includes Jackson Browne, Steve Earle and the Dukes, Cyndi Lauper, Emmylou Harris, Chris Isaak and more than 100 other acts performing across seven stages. The gregarious Chicago singer, a member of the iconic gospel group the Staples Singers, played a set bursting with old favorites, new recordings and a few well-chosen covers, including her sultry take on Buffalo Springfield’s “For What It’s Worth.” Greeted by sunny skies - a wholly unfamiliar sight in the city’s Richmond District in the days leading up to the festival - the young, shaggy Southern rock duo Jamestown Revival kicked off the festival on the Arrow Stage on Friday afternoon with a set of cagey songs that reeked of bourbon and sounded like they were written on the backseat of a Harley. Representing the old guard - which has thinned out considerably over the years -- the Dry Branch Fire Squad paid tribute to mandolin player Ralph Thomason’s former band leader, the late Ralph Stanley (“He’d been like a father to me,” he said). There was plenty of old school foot stomping, fiddling and tap dancing on the Swan Stage amid a sea of eclecticism, with everyone gathered around one microphone blissfully blazing away. With wind blowing through his silvery hair, dark aviator glasses covering his eyes and cache of ‘70s era hits in his back pocket, Texas native and longtime San Francisco resident Boz Scaggs looked thoroughly in his element on the Banjo Stage. [...] he really killed it with the shimmering disco era anthem “The Lowdown,” which sounded as fresh now as the day he recorded it. “I’ll never forget being 16 and coming to this festival -- it was kind of a life changer,” Delta Rae singer Elizabeth Hopkins told the crowd during her band’s early afternoon set on the Arrow Stage, during which the North Carolina sextet performed a bunch of high-octane folk-rock tunes, joked around with the crowd (This next song is about the presidential election - it's called 'Scared, keyboardist Eric Hölljes said) and got people up and moving. The band also brought out students from the Oakland School of the Arts to add their powerful voices to a song about racial injustice that included the refrain, “All you good people, won’t you come around/ Defend your brothers!”