>If cruise lines, like Carnival, want to make cuts, why not cut out things like art auctions at sea or the MANY bingo games which require at least 3 staff members to supervise etc.[/QUOTE]
I'm not trying to be snotty here, but you answered your own question. Musicians are an expense; art auctions and bingo produce revenue.
I also suspect that Carnival (and other cruise lines) struggles to find and keep good musicians.
I'd love to be a fly on the wall in Carnival's accounting office in Miami and see how they weigh expenses vs. revenue for the different aspects of shipboard entertainment. I'm guessing they have it down to a pretty good science, and, naturally, follow the money!