Dead Poodles is a famous rock band. The lead singer is Wendy Leather. The popularity of the band is based almost solely on the vocals of the lead singer. The band is engaged by Rock Promotions Inc. to give a concert on Canada Day on Parliament Hill in Ottawa to an expected crowd of 100,000. The day before the concert, Rock Promotions receives a fax from Wendy stating that she will not be attending the concert because she is getting married that day. Wendy sends her sister, Candy Leather, to sing in her place. The concert is a big success. Even though the crowd is disappointed not to hear Wendy, they love Candy.

Can Rock Promotions sue the Dead Poodles for breach of contract? Explain from both parties perspective.