Botanically speaking, this is a crossbreeding of the 5th Avenue Theatre and ACT Theatre, and it’s one of the most successful ever: 5th Avenue–level singing in the intimacy of ACT. Maybe it’s not a Mendel-discovering-genetics-with-his-pea-plants level of world-changing greatness, but Little Shop of Horrors is revelatory, satisfying material, blackly funny, a marvel of language. And a painful reminder, as if there were any doubt, how freaking brilliant playwright and lyricist Howard Ashman was, not to mention how handsome (seriously, do a Google image search of Howard Ashman). (ACT Theatre, 700 Union St, acttheatre.org, 7:30 pm, $49–$79, through June 15)