While a hiatus invariably leaves room a return, the Black Crowes are leaving fans with the impression that the band is calling it quits, having spent more than 20 years banging out all kinds of classic rock riffs with a Southern-blues jam flare. The work is as varied as their breakout record, “Shake Your Money Maker,” and its chart-topping singles “Hard to Handle” and “She Talks to Angels,” and their recently released “Croweology,” a double disc of acoustic recordings of past work. With just a few dates left before concluding their “Say Goodnight to the Bad Guys” tour in San Francisco, the Black Crowes are scheduled to perform a double set — one acoustic, one electric — at the National on Tuesday, Nov. 16, at 7 p.m. $35-$38. 612-1900.  — Mike Hilleary