High-tin bronzes of copper containing 22 to 24 percent tin can be shaped after casting by hot forging. If these bronzes are then quenched from above 520°C, the forgings are much more ductile than if allowed to cool in air. The alloy, when formed by forging and quenching, produces a sonorous metal whose principal, although not only, attested archaeological occurrence is in cymbals and gongs. Metallographic examination of samples of gongs used today in Ifugao, Philippines, indicates that the quenching procedure determines not only the softness and ductility of the metal, but also its durability. Improper quenching results in a distinctive microstructure which is associated with most of the broken objects. The microstructure observed in these objects, that of the massive transformation, is reported in a copper-tin alloy for the first time. -- AATA