Well, the quality of accommodation depends on the cruise line and even the individual ship. The rooms are usually going to be small and shared with one other person, though a band leader may end up with a cabin to themselves depending on the situation. The cabins I've lived in, while small, were nice enough, and having someone come in to clean and tidy every day really helps. Standard cabins on any of the major lines are going to have a couple of single bunks, a desk, a small cupboard/closet for each person, a desk and a small bathroom with stand-up shower. Newer ships often have internet access piped right into individual cabins, and other conveniences.