I peruse eBay quite looking at 5-String Banjos. I've noticed that the older ones, e.g. late 1800's early 1900's S.S Stewart etc. were all open back. When did the Resonator/Tone Ring appear and who was the first manufacturer. I'm sensing it was Gibson in the early Twenties. Did resonators on Tenor and Plectrum banjos pre-date their Five String counterparts to be heard over Jazz bands?