Review: ‘Freestyle Love Supreme’ expertly treads the tightrope of improv

If “gerund” isn’t the very last word I ever expected to hear uttered on a Broadway stage, it’s probably pretty darn close. Broadway rarely gives grammar lessons, after all.  And yet there it was, being blithely tossed out by Anthony Veneziale toward the beginning of a performance of “Freestyle Love Supreme,” the jubilant evening of improvised rap over which he was presiding with embracing geniality at the Booth Theatre.  What can I say? Veneziale, and the show, had me at “gerund.”  Without belaboring this business, I would just observe that a performer who can casually dredge up that rather archaic…