Frank Ocean canceled overseas dates last week due to a torn vocal cord, and now he's brought his problems back to North America. The R&B singer has been forced to cancel his North American tour dates including a headlining spot at Drake's OVO Festival in Toronto this coming Sunday.

OVO - which was to run Aug. 4 and 5 -- is issuing refunds to event-goers who had tickets for its first date, which also hosted James Blake on the marquee. Blake will now be on the Aug. 5 lineup along with the fest founder Drake and his special guests, and Sunday's festivities are now canceled.

Ocean's stops in Australia and in Montreal were curbed last week due to his medical condition. No word yet on when he expected to recover from the tear.

"After last night's [July 25] concert ... it was necessary to seek medical advice due to vocal issues Frank Ocean experienced during the show. It has subsequently been confirmed that Frank has suffered a small tear to one of his vocal cords and has received medical advice that he must rest his voice," Live Nation said last week.

Prior to his vocal issues, Ocean had previewed three new tunes while he toured in Germany late last month. Check out one of those: