Rihanna has been forced to cancel her concert in Boston tonight.

The "Stay" singer - who kicked off her new Diamonds world tour on Friday night - has come down with a severe case of laryngitis but is hoping a two day break from performing will cure her in time for her next concert in Baltimore on Tuesday.

Live Nation shared the 25-year-old star's disappointment with gossip website TMZ.com earlier, saying, "Unfortunately, following her sold out concert on Friday, Rihanna has contracted laryngitis and per doctor's instruction is unable to perform this evening." But they said she is still scheduled to play a show in Baltimore on Tuesday, and her Boston show will be rescheduled.

A source previously claimed that Rihanna couldn't wait to get out on tour and took it easy in rehearsals so she could save her energy for her fans. "She's good, excited to kick off this [tour] and do it big. She's already hyped up and doing some light rehearsals but other than that, she's taking it easy. Saving all the energy for the show," an insider said.

The singer was also said to have prepared for her new world tour with the help of her mother and boyfriend Chris Brown. Chris has been in constant contact with the "We Found Love" singer while Rihanna also turned to her mother Monica as she prepared to hit the road. "Chris wished her a good show a few nights ago. She been talking to her mom, you know, getting her head right," a source said.