There comes a point in almost any scheduled performance by Jon Batiste
when he pops up from the piano and strides into the crowd, tootling his
melodica, a toylike wind instrument, with bandmates in tow. It’s a
trademark shtick that happens to carry a whiff of the authentic, given
Mr. Batiste’s lifelong familiarity with New Orleans second-line parades.
Naturally, it was one of the factors that led to his role as bandleader
on “The Late Show With Stephen Colbert,” which makes its debut on CBS on Tuesday.