Was Brain May the first to come up with this technique? If so, did anybody repeat the same method of playing?

I love this!

Absolutely brilliant song. Kills me that the rag time dixieland stuff is all guitars. Genius.

I remember reading that Brian's dad was really into jazz when he was young and they would listen to a lot of that music together. That was what inspired the tune.

As to other folks replicating the sound, I know I've never heard anything else quite like it.