Specimen rods which had been cooled similarly to bell-castings, and test bells were used to study the structure and acoustic properties, e.g. elastic modules and density, and the mechanical data as a function of alloy composition. The variation in density caused by porosity had a significant effect on the attenuation properties. Third alloy constituents were studied systematically for the first time. The speed and attenuation of sound are more affected by P, Al, Mg, and Bi than by Pb. However, variations in beli size and density have a greater bearing on the sound than changes in alloying composition and impurities. 24 ref. -- AATA