The Regina Music box's rich sound remains unsurpassed in America and elsewhere as the mechanism for the instrument differs from others of the period. The Regina tune sheets are steel discs with the printed song title and logo directly on the disk. The metal projections below the tune sheet hit a star wheel similar to a clock gear as the disk passes. The interchangeable music disks made by Regina would fit all of their boxes of the same size. These interchangeable disks or tune sheets as they were called at the time of their introduction in the late 19th Century are typically white in color or silver in color with a printed Regina logo and other graphic designs. Regina music box serial number lookup.