Now this isn’t me, but a friend of mine who’s a singer proposed by writing and singing a sing he wrote for her, in front of family and friends at a coffee house she runs for her church group (he performed there often, so it wasn’t very obvious what he was doing, but she found out before hand) but he wrote a break into the song where he got down on one knee and proposed. It was actually really sweet, and the song was amazing.
I think a lot of people are opting to include friends and family these days, as opposed to just the one on one proposal.