[Note: This post has been updated (1) as of 6:13 PM Eastern on 23 Aug. See below.]
You've all, at one time or another, heard the mambo (one of the five dances from "The Dance At The Gym" episode) from Bernstein's West Side Story, right?
That's what you think.
Scoot on over here, scroll down a bit, give a click on the video, and hear it played by a bunch of kids.
Wherever he might be, Lenny must be smiling from ear to ear.
(Our thanks to Deceptively Simple for the link.)
Update (6:13 PM Eastern on 23 Aug): Here's the video itself. The orchestra is the Simón Bolívar Youth Orchestra of Venezuela, and the conductor is, of course, the new music-director designate of the Los Angeles Philharmonic, the 26-year-old Gustavo Dudamel.