Debbie Davis has always been a musical polymath, with a wide-open definition of what qualifies as a jazz song: Material on this live disc ranges from Duke Ellington to the Beatles (twice) to Tom Lehrer to Alex McMurray, which covers 80 years and a few different worlds. What the songs all have in common is vivid characters in the middle of loving, sinning or both—just what a resourceful singer needs to get her voice around.

Davis has usually worked in bigger groups, but here she’s joined by Josh Paxton, a pianist whose instincts are every bit as flexible as her voice. Give them a gorgeous tune (Fats Waller’s “Jitterbug Waltz”) and they’ll do some graceful variations; give them a lusty one (“Lulu’s Back in Town”) and they’ll cavort with it. Their version of “Lady Madonna” is one good example: Before the tune, Davis jokingly tries to rattle Paxton by noting that Fats Domino had covered it with James Booker on keys. And they wind up expanding on both familiar versions: During the first solo, Paxton plays it Paul McCartney–style while Davis sings the horn line; but for the second one, he takes off on some wild, Booker-esque invention. There is in fact no piano solo on the Domino/Booker version, so here Paxton shows what Booker might have played.

Paxton can also match Davis’ sense of mischief: They approach Tom Lehrer’s “Masochism Tango” as a steamy torch song, which of course makes it funnier. But the best track here is also the biggest surprise, Amy Winehouse’s “Love Is a Losing Game.” The song was written to be a heartbreaker—and of course, the original singer was no slouch herself—and they get the mood and the atmosphere just right, making this a performance for sad romantics everywhere.

Debbie Davis & The Mesmerizers perform at Jazz Fest on Saturday, May 6 at 5:35p in Economy Hall.