Marion, Among the Italian speakers at the homes where I play, I find that "Oe, Mari!" is very popular, as is "Luna Mezz'o Mare!." I have also had requests for La Spagnola. "Ciribiribin" and "Funiculi! Funicula!" have also been popular in the US in the earlier part of the 20th C.

At Christmas time, try "Gesu Bambino" and/or "Dormi O Bel Bambin'."

Re requests, they usually yell them out in the middle of whatever song I'm doing. (Just kidding -- that only happens occasionally.)
People often do spontaneously call out requests. I usually honor them, but not necessarily right at that time, unless it fits in with the overall structure of the program. (E.g., I don't like to do several slow songs in a row.) In a general sing-along, I usually do ask for requests from time to time throughout the program.

leneeia, of course individuals' hearing losses will vary, but according to those who work with the hearing impaired elderly, losses at high frequencies are more common, and generally folks can hear the human voice better at the lower ranges than at the higher.

It's also true that some hearing aids make the wearers hypersensitive to high-pitched noises, so that talking loud (or singing) at a high pitch tends to hurt their ears.

Genie