Date Range: c1897 – c1960
Shellac discs (commonly called 78s) are usually coarse-grooved, of 10 or 12 inches diameter and play at 78 rpm (revs per minute) with a duration of three to four minutes per side. They usually only have one track per side.
Five inch, eight inch, twenty inch and other sizes are occasionally seen and speeds can range from between 70 to 90 rpm.
Shellac discs are heavier and more brittle than vinyl discs.