Even back when she was a hotshot young bottleneck guitarist making her name in the early 1970s, Bonnie Raitt's blues-suffused music conveyed old-soul wisdom and empathy.

So it's not a big surprise that her music has aged as gracefully as she has, now that the 62 year old redhead has lived as long as the blues men and women she apprenticed under back when she was a Radcliffe dropout living at 17th and Lombard and serving a musical apprenticeship at the Philadelphia folk club the Second Fret.

On Saturday night before a packed house at the Academy of Music – a room she remembered seeing The Band perform at in 1969 – Raitt played an ingratiating 90 minute set in support of Slipstream, the new album that's her best since the run of LPs like Takin' My Time (1973) that predated her commercial breakthrough with 1989's Nick Of Time.

Raitt fronted her longtime touring band, augmented of late by Hammond B-3 whiz Mike Finnigan, who took the mic for a spirited rip through Ray Charles' "I Got News For You" that allowed the leader to stretch out most satisfyingly on guitar. Raitt's slide provided a sharpened edge to John Hiatt's "Thing Called Love" and Bob Dylan's lament "Million Miles," one of four Joe Henry-produced tracks that are Slipstream's standouts.

Along with blues woman swagger, Raitt's appeal is built on a nuanced, probing way with quieter broken-heart songs. The crowd pleaser was the soft ballad "I Can't Make You Love Me" from her biggest seller, 1991's Luck Of The Draw. But better still was the emotional centerpiece, a partly a cappella, partly spoken reading of John Prine's "Angel From Montgomery," delivered in a full-of-feeling alto that benefited from the nearly four decades passed since Raitt first recorded it.

Foo Fighters leader Dave Grohl, said to have twice left bartenders a $1000 tip on a recent stay in Philadelphia, is often called the nicest guy in rock. His female counterpart is surely Raitt, who on Saturday thanked by name her sound man, guitar tech and concert promoter, as well as singling out all of her band members several times over.

She talked about riding bikes along the Schuykill with guitarist George Marinelli the day before, and dedicated songs to Philadelphia institutions such as the Rhythm & Blues Foundation, American Friends Service Committee and deejay Michael Tearson. And after closing with a reggae groove on "Have A Heart," she asked her audience to do her a favor. "It looks like an auction," she said. "But it's an election. Go vote."

The life force that is 72 year old gospel powerhouse Mavis Staples opened with a roaring set. Highlights included a rousing version of The Band's "The Weight," a hushed take on the title cut to her 2010 album You're Not Alone, and a spontaneous-seeming "Will The Circle Be Unbroken?" with Raitt, who she referred to as her "baby sister." When the headliner came back out, she called Staples "an intergalactic treasure," took a look around the 155 year old opera house and observed: "Mavis really classed up this place, didn't she?"

Below are clips of Raitt doing the Slipstream single "Used To Rule The World" at this year's New Orleans Jazz Fest and Staples singing The Weight with Wilco and Nick Lowe.

Previously: Kinky and Kiwanuka at the World Cafe Live Follow In the Mix on Twitter here