Back in 1910, when records were still made out shellac, 10-inch discs spun at 78 revolutions per minute (RPM). In 1948, when the 33 1/3 RPM vinyl LP was introduced, the 10-inch disc was still the industry standard. Twelve-inch records were also pressed, but they were saved for classical music. As it turned out, everyone wanted those extra grooves—by the mid-1950s, 10-inch records had been largely phased out, which is what makes them so...Continue Reading