Take three jazz elder statesmen, saxophonist Lee Konitz (82), bassist Charlie Haden (72), drummer Paul Motian (79), add 39-year-old pianist Brad Mehldau, set them up at NYC’s famed Birdland club with recording gear, and you have an instant jam session, right? Not this crew! While the set list looks like bop standards, the playing is far looser and more imaginative than might be expected. Themes are teased out of free improvisations, as in “Lullaby of Birdland.” Their take on the warhorse “Lover Man” is worlds away from Billie Holiday’s, featuring highly melodic piano soloing. “I Fall in Love Too Easily” is a hushed exploration of the song that, perhaps until now, Miles Davis had made his own. Sonny Rollins’ “Oleo” closes the set, with Konitz probing the lower register of his instrument (a nod to the composer?). Lengthy renditions of “Solar” and “You Stepped Out of a Dream” round out this engaging disc. Jazz neophytes may ask, “Where’s the melody?” But aficionados will relish the subtle sense of adventure here.