Katy Perry wants you to bear “Witness” to her latest album and tour. (Getty Images)

Katy Perry
Verizon Center, Sept. 25, $50.50-$200.50.
Katy Perry finally announced her new album “Witness” this week (it’s already spawned two singles: “Chained to the Rhythm” and “Bon Appetit”) and an accompanying tour. The album drops June 9 — buy a ticket and get a free copy.
Get tickets: Monday at 10 a.m. through Ticketmaster.

Khalid
Fillmore, Aug. 5, $25.
Texas-based R&B singer Khalid made a splash last year with his laid-back single “Location,” off his acclaimed debut, “American Teen.”
Get tickets: Friday at 10 a.m. through Live Nation.

‘Mystery Science Theater 3000’ Live!
Lincoln Theatre, July 9, $39.50-$49.50.
Netflix’s “Mystery Science Theater 3000” revival is going on tour, with creator Joel Hodgson and new host Jonah Ray bringing riffing, robots and B-movies to two different shows.
Get tickets: Friday at 10 a.m. through Ticketfly.

David Grisman Bluegrass Experience
Hamilton, Oct. 13, $35-$80.
Mandolin master David Grisman, who has been touring of late with fellow string band icon Del McCoury, is coming back to The Hamilton with his own Bluegrass Experience band.
Get tickets: Friday at 10 a.m. via Ticketfly.