Joan Baez has a brand-new album out. She's also currently celebrating 50 years in the industry. And the vocalist is in the midst of a national tour, which touches down at the Herbst Theatre in San Francisco on Tuesday and Wednesday.

Peace activist and singer Joan Baez performs on stage during a free performance on the National Mall near the Ellipse in conjunction with anti-war demonstration Saturday, Sept. 24, 2005 in Washington. (AP Photo/Pablo Martinez Monsivais) ( PABLO MARTINEZ MONSVAIS ) Yet, anybody who knows anything about Baez - arguably the quintessential female protest singer, and one who has lent her voice to countless social reforms and political drives - should know that music isn't the first thing that she wants to talk about these days.

"I'm just as elated as the most elated person out there," says the 67-year-old Woodside resident during a recent phone interview. "I feel like Obama's not going to embarrass me. And I'm tired of being embarrassed."

The folk music legend seemingly always has been interested in social and political issues. She committed her first act of civil disobedience as a 16-year-old student at Palo Alto High School, when she refused to participate in the school's air-raid drill, and she's been busy fighting the good fight ever since.

Her efforts continue with her new album, "Day After Tomorrow." The 10-track record offers stirring commentary about the state of modern affairs, most emphatically addressing life during wartime, which she does through such exquisite gems as the Elvis Costello-T Bone Burnett composition "Scarlet Tide" and the Tom Waits-penned title track. The latter, originally released on the eccentric songwriter's "Real Gone" (2004), is a real stunner, one that perfectly fits Baez's three-octave voice.

Baez says she was "knocked out" the first time she heard Waits' "Day After Tomorrow."

"It was one of those songs where there was no question that it was right for me," she says. "I'm just glad that (Waits) wrote it."

Other highlights from the record include the newly penned compositions "I Am a Wanderer" and "God Is God," as well as the a cappella workout on "Jericho Road." All three of those tunes were written by alt-country/Americana star Steve Earle.

The album is the third offering in what might someday be commonly referenced as Baez's "Steve Earle era." That chapter of her career began in 2003 with Baez's "Dark Chords on a Big Guitar" album, which featured what many consider to be the definitive interpretation of Earle's "Christmas in Washington."

That gorgeous, forlorn number has become a Baez concert staple, one that is as eagerly anticipated by fans as any of the singer's classic hits (such as her covers of The Band's "The Night They Drove Old Dixie Down" and Phil Ochs' "There But for Fortune").

"It's a highlight every night," Baez says of her performances of "Christmas in Washington." "There's something about that song that really connects with the audiences."

The relationship between singer and songwriter would strengthen with the 2005 live disc "Bowery Songs," which included a rendition of Earle's "Jerusalem," and rise to new heights with "Day After Tomorrow."

Besides contributing songs to the album, Earle played guitar and other, lesser-known instruments (harmonium, anyone?), added harmony vocals and served as the producer on the new album. The collaborative effort has proved to be a modest hit - "Day After Tomorrow" debuted on the pop charts in September at No. 128, marking Baez's first entry into the Billboard Top 200 in 29 years. (Her last album to chart was 1979's "Honest Lullaby," which hit no. 113.)

What's more significant, however, is that Baez is happy with how her latest collaboration with Earle turned out.

"This record is really what I wanted it to be," she says.

"Day After Tomorrow" is Baez's 24th studio album, and the latest chapter in one of popular music's longest-running success stories. What would she have said, one wonders, if a person would have told her back in 1958 that she was embarking on a 50-plus-year musical career?

"When you are at that age, you don't really think in years," she says. "I would have probably looked at (the person) and changed the subject."

Which is pretty much what happens when talk turns to her 25th studio album. She hasn't put much thought into it, but her hunch is that it will reflect the results of the recent presidential election.

"I think (I'll ride) this wave of general excitement, of Obama Land," she says. "I think that will probably influence whatever I do next."