|00:48Mastertone banjos are made by the Gibson company. They defined the bluegrass banjo form when the first bluegrass banjo players chose them over other popular banjos of the period. They are characterized by a heavy bronze tone ring, resonator metal flange with distinctive holes and one or two metal coordinator rods that attach the neck to the pot.
Mastertones were first advertised in 1919, and had the so-called "trapdoor" resonator and ball-bearing support for the tone ring (no springs). Entire books and definitive articles have been written about these banjos. Suffice it to say that prewar Mastertones are the most sought after bluegrass banjos with much the same mystical quality boasted by prewar Martin Guitars and Lloyd Loar F5 mandolins.