NEW YORK, NY - NOVEMBER 20: Rihanna performs at Webster Hall during her 777 tour on November 20, 2012 in New York, United Sta
Kevin Mazur

Rihanna just kicked off her Diamonds World Tour on Friday night, and unfortunately she's already canceling a show. 

The "Stay" singer was scheduled to appear tonight in Boston, but a bout of laryngitis is forcing her to postpone the show. 

Live Nation released the following statement: "Unfortunately, following her sold out concert on Friday, Rihanna has contracted laryngitis and per doctor's instruction is unable to perform this evening."

Tonight's cancelled show is expected to be rescheduled. RiRi's next show is set for Tuesday in Baltimore. Her 25-city tour wraps up at Brooklyn's Barclays Center on May 4.

RiRi tweeted: "#Boston this is the hardest thing for me to deal with! I feel like we've been waiting on this day forever, and I'm hurt that I let you down." And "I hate disappointing people that never ever let me down!! I'm so embarrassed about this! Thank you for your prayers and well wishes! #DWT."