Dire Straits is something that happens to you, it would be used in this context, 'He was in dire straits' meaning, in big trouble of some kind. The straits in q

Dire Straits is something that happens to you, it would be used in this context, 'He was in dire straits' meaning, in big trouble of some kind. The straits in question are not a plural of an individual living thing like a Beatle. So I would say 'Dire Straits is a band'. I'm a native British English speaker, that sounds right to me, but my generation weren't formally taught grammar at school so I can't back that up with any fancy grammar words!