Karen O attends the 30th Annual Rock and Roll Hall of Fame Induction Ceremony Show on Saturday, April 18 in Cleveland, Ohio. Credit: Dimitrios Kambouris/WireImage for Rock and Roll Hall of Fame

Well, it's out in the open now! Karen O, lead singer of the Yeah Yeah Yeahs, is pregnant with her first child. The indie rock artist, 36, announced her pregnancy without saying a word at the 30th Annual Rock and Roll Hall of Fame Induction Ceremony Show on Saturday, April 18 in Cleveland, Ohio. 

The musician, whose real name is Karen Lee Orzolek, performed at the event in honor of the late Lou Reed

"Lou is being inducted into the Rock'n'Roll hall of fame Patti is inducting him and me and @little_vampire will be there to sing a song in his honor #hellocleveland!" Karen O wrote on Instagram, later tweeting, "Laurie recited Lou's 3 rules to live by- be afraid of no one, get a bulls--t detector and learn how to use it, have tenderness.  YES."

Stepping on stage in a skintight black minidress, the rocker's baby bump was out there for all to see after months of sporting baggy ensembles at recent events. 

Also daring to bare was fellow performer Miley Cyrus, who rocked heart-shaped pasties with "J's" on them in honor of legendary artist Joan Jett. Other stars in attendance included John Legend, Stevie Wonder, Bill Withers, Paul McCartney, and Dave Grohl.

Karen O married director Barnaby Clay in 2011. The pair last walked a red carpet together at the 2014 Vanity Fair Oscars after party.