Paul Simon, right, and Art Garfunkel perform during the 25th Anniversary Rock & Roll Hall of Fame concert at Madison Square Garden in New York, on Oct. 29, 2009. ((Henny Ray Abrams/Canadian Press))

Paul Simon and Art Garfunkel have cancelled a concert in Calgary Sunday night because Garfunkel is suffering from a throat problem.

The legendary folk-rock duo was slated to play the Pengrowth Saddledome May 2. The concert has now been rescheduled for July 5.

Concert promoters Live Nation said tickets for the orginal date will be honoured at the July 5 concert. Refunds will be available from May 2 to July 5, the company said.

Fifteen other concerts in Canada and the U.S. have also had to be rebooked.

"A vocal strain recently sustained by Art Garfunkel," is behind the postponement, according to the tour website.

"The dates have been rescheduled to allow for an adequate period of rest and rehabilitation, after which Art is expected to make a complete recovery."

Simon and Garfunkel have made a number of concert appearances together since their second breakup in 1969.