Who or what is known as 'the papas'?

Which performer is associated with 'tennille'? Who or what is known as 'the dominos'? What does this describe: the e street band? Who or what is known as 'the heartbreakers'? What does this describe: the silver bullet band? Who or what is known as 'the tijuana brass'? Based on the clue 'this is an extension of the initials us', what is the answer? What is referred to by 'tobago'?