Your Mother Should Know: Brad Mehldau Plays the Beatles Brad Mehldau Nonesuch Records   Pianist Brad Mehldau is a chameleon-like figure, able to play music in many styles and a creative composer. He excels at finding new standards, recent pop songs that benefit from jazz treatment. The Beatles’s songbook is among the most durable in the pop canon, having endured numerous revisionings, some inspired and, sadly, some insipid. Your Mother Should Know: Brad Mehldau Plays the Beatles is strongly inspired.    A live recording that consists of ten Beatles songs and a David Bowie encore (“Life on Mars”), the