Harmony Disc Records was a Chicago-based record label launched by the Great Northern Manufacturing Co. in 1907. It produced 10-inch shellac records that were identical to other disc records of the time, except for a large centre hole of ¾-inch diameter. The larger hole was so that only Harmony Disc Records could be played on the Harmony Talking Machine.
Harmony was one of a number of Chicago-based labels that operated a premium scheme whereby the phonograph itself was inexpensive but the purchaser was locked-in to purchasing discs made for the player since the player had a correspondingly larger center spindle to prevent discs with standard holes fitting onto the turntable.
Harmony Disc Records were sometimes single-sided in the early days, and all were 10-inch in diameter.
Around 1912, Great Northern Manufacturing Co. left the record business, and Columbia took over the Harmony Disc Record label, which was renamed Harmony Record with the company name as Harmony Talking Machine Co. Columbia resurrected the Harmony name in 1925, but this time with a standard centre hole.
As well as the Harmony Disc Record, the other Chicago-based labels included Standard Disc Record (½-inch centre hole), United Records (1½-inch centre hole), Aretino Records (3-inch centre hole), and Busy Bee Records (rectangular cut-out in addition to standard ¼-inch centre hole).
In 1916, Harmony, Standard, United and Aretino were brought together under the Consolidated Talking Machine Company. It’s unclear when the Harmony Record label was discontinued and it may be that like the Standard Disc Record label, some recordings would have been available for a while with the larger centre hole.