Wish I could afford a jazz cruise. Love the music.
On the general topic of how crew and pax interact, I think that some of it is just the normal variation in how people perceive each other. Sometimes we relate to each other, sometimes not. The crew is almost always too professional to show it if the answer is "not". But, sometimes a small connection is formed. Not talking friends for life, but just a true interest in each other. When we took our 2 nephews on a cruise several years ago, our waiter was from Russia and had been in their special forces in the military. The boys (19 yrs old), and my husband and I, were truly fascinated by some of his stories and he did spend some extra time talking with them. I think he liked their interest and sharing his stories. Who doesn't like talking about themselves to someone who really wants to hear it?
On some of our longer, more expensive cruises, we have run into some true repeat passengers. Some were very nice to the staff and tipped well, as far as we could tell. But, others were so elitist that they were an obvious pain. Used to having servants perhaps. Don't need to tip them if you are their employer! We even ran into a tablemate who raised hell when a hurricane delayed our cruise an extra day. We were happy to have a free bonus day at sea, but he obviously blamed the staff. Did everything but stamp his feet like a child. Pathetic, in my book.