Carrie Underwood and Bo Bice were competing against each other in Season 4 of American Idol, but they were also IRL friends.

Backstreet Boys and Rascal Flatts capped off the 60th Academy of Country Music Awards with a collaborative performance that celebrated singing in perfect harmony, whether country or pop. Members of ...

Backstreet Boys and Rascal Flatts capped off the 60th Academy of Country Music Awards with a collaborative performance that celebrated singing in perfect harmony, whether country or pop.