After canceling the Pittsburgh stop on her "As I Am" concert tour last night (April 22), Alicia Keys must cancel a second show due to swollen vocal chords. This comes just after opening act Jordin Sparks dropped off the tour on April 21 due to an acute vocal cord hemorrhage.

Ticket holders for the show originally slated for tonight (April 24) at Cleveland's Wolstein Center and the Pittsburgh date may contact the respective venues for instructions on how the tickets will be honored. Tickets for the Cleveland concert can be used for the upcoming show in Columbus, Ohio.

Keys is currently being treated by a physician and expects to return to the tour on April 26 at the Value City Arena at the Jerome Schottenstein Center in Columbus.

Meanwhile, Sparks was forced to cancel three shows last weekend, including the opening night of Keys' tour Saturday in Hampton, Va., and an Earth Day gig on April 20 at Washington, D.C.'s National Mall. A Jive Records representative told Billboard.biz that Sparks will rejoin the tour in May.

Keys' "As I Am" has sold 3.4 million copies to-date, according to Nielsen SoundScan.