The young man with the knowing smile above — and trust me, he already knows much more than me about a growing pile of stuff  — is my son, Ethan. He plays piano and keyboards. His professional debut was at Sidney’s Lounge on St. Bernard Avenue in New Orleans, where the estimable Kermit Ruffins, tending bar that night, made him sit and play four songs on the battered upright. He nervously gave up two Fess standards and some Fats Domino. He was fourteen. Somewhere on the internet, if you google Ethan Simon, you’ll find an audition video of him playing bop for admission to an summer jazz camp. He goes to work on Kern’s “All The Things You Are” and Charlie Parker’s “Now Is The Time.” He was seventeen then. He’s now just shy of his twenty-first birthday, and his band, The Intrinsics, of Cambridge, Mass. and whatever parts of greater Boston require the services of a Memphis-style soul outfit, has just dropped its first...