WHEN IT COMES to things Jewish, Sean Altman doesn't pull punches. Especially this time of year.

Hanukkah, he believes, was invented so Jewish kids "don't feel neglected in the Christmas season."

And even some of the most assimilated grown-up Jews have trouble dealing with the big Christian holiday, he argues.

"We're not talking about the ones that wrote the best Christmas songs - like 'White Christmas,' 'Silver Bells' and 'Let It Snow,' " Altman name-dropped with a wink.

That's why this comical singer/tunesmith/tummler goes into performance overdrive in December with a pointed package of musical mayhem and identity-raising he's trademarked as "Jewmongous." While most other touring musicians lay low, Altman's playing 'em again, Sam(uel) straight through the season, with a return visit to the Milkboy Coffee in Ardmore on Saturday.

Truth is, you don't have to be of his faith to enjoy this very amusing (though sometimes painfully so) Heb-centric song and quip-athon, which this time features guest appearances by Cynthia Kaplan, a singer/songwriter "who looks very prim and proper but works blue" - as does Altman.

"I like to say this is a show for the family only if you're raising your kid to be a sailor," he shared.

Also in the concert mix will be Altman's "backup band" of one - a cajon (Mexican box drum) percussionist who parlays the wide span of Altman's rhythmic ideas without drowning out the funny lyrics of which he's especially proud.

Altman also delights in ribbing the "30 percent of the audience that isn't Jewish" at his Jewmongous nights. All to miss-explain the cultural and religious references he also mangles in songs like "What the Hell Is Simchas Torah?" his cabaret-toned circumcision lament "Another Inch," his rant on anti-Semitism "Blame the Jews," and the Passover-themed "They Tried To Kill Us, We Survived (Let's Eat)," which retells the story of the Exodus from Egypt with a Pharoah "who looks like Yul Brynner," a Moses played by Charlton Heston and a cavalcade of cameos from Adolf Hitler to Madonna.

"Some people think I'm a serious, scholarly person. But if you listen closely, I'm more the 'Bart Simpson of the Yeshiva' [religious school]," Altman said. "I was there, but hiding in the back row, scribbling all through class. I barely heard a thing."

And even if you've heard all those gems from the "Jewmongous" album Altman put out a few holidays ago, rest assured the guy's got a mess more, including his new Prince-like salute to this year's "1999th" anniversary of Jesus' bar mitzvah (do the math) and myth-building "Reuben the Hook-Nosed Reindeer." Who dat? "Santa's forgotten reindeer who does all the dirty work - the accounting, the packing up of the sleigh. Reuben's also the one who gets all the good deals on supplies for Santa."

Ironically, when Altman isn't into his Jewmongous shtick, he's often working with an alternative a capella group the GrooveBarbers, which spun a very sincere (though as nonsectarian as possible) Christmas album called "Glory." The man also moonlights in various a cappella groups that work Orthodox Jewish celebrations held on the Sabbath "when you can't have instruments playing. I've phonetically learned all these old world Hebrew songs, but honestly have no idea what I'm singing."

Altman's first and still biggest claim to a cappella fame was as a founding member of Rockapella and co-author (with David Yazbek) of the group's theme song for the long-running children's TV show "Where In the World Is Carmen Sandiego?"

Actually, Altman's been a musical playmate of Yazbek's since they harmonized at the Riverdale Country School in Bronx, N.Y., as Moon Pudding, a Simon and Garfunkel-like duo fondly recalled by People Paper columnist Howard Gensler, who had friends in common with Altman and owns an original cassette of the pair. Now Altman hopes to follow Yazbek's path (as composer of "Dirty Rotten Scoundrels" and "The Full Monty") into the wonderful world of musical theater. "I've got an idea for turning the Jewmongous material into a theatrical event - either a revue or a book musical," Altman dreamed out loud.

And here's hoping one that will last long past Hanukkah.

Jewmongous in Concert, Milkboy Coffee, 2 E. Lancaster Ave., Ardmore, 8 p.m. Saturday, $15 in advance, $18 day of show, 610-645-5269, milkboycoffee.com.

Blog: philly.com/GizmoGuy