A copper metal mother for OKeh matrix # W81572, "Since My Best Girl Turned Me Down," by Bix Beiderbecke and his Gang. This item was recently offered for sale on Ebay.
_______________________________
The abundance of vintage recordings available on LP records and compact discs often makes music enthusiasts wonder how the music makes the transition from shellac to modern media.
Record collectors, too, have their curiosity piqued when they examine or listen to a newly-acquired record and discover that they have found something that is slightly different from its well-known version. Discovering an alternate performance invariably leads collectors to ask, "How many alternate versions of this performance were recorded?" How many were released? And how many of them still exist?"
Most people assume that the answers to those questions lie in the vaults of major record companies, and in the metal parts held there in storage.
Perhaps the best way to introduce you to a recording company vault is to let you see one for yourself. This 1942 film, narrated by the noted opera critic Milton Cross, explains in detail how RCA Victor manufactures its records. It also includes a segment inside the vault, where a guard shows metal parts for records by Sousa, Chaliapin, and Caruso. This is part one of the film; part two is here.
(By the way, the main building of the "Camden Plant of RCA Victor" shown in the opening sequence of the film -- the building with the 3-story clock tower visible -- has recently been renovated and reopened as The Victor, a luxury apartment complex. The rest of the plant was demolished decades ago. More about that further down ...)
The process for making shellac (or vinyl) records is rather complicated. After the wax (or lacquer) matrix is engraved with the sound from the cutting stylus, it is placed in an electroplating bath, where it is plated with copper. After the copper plating, the wax is stripped away and the metal master is plated again with nickel, and then given a special coating that allows additional layers to be electroplated onto it and then removed.
The metal master is then electroplated again and again, each time producing a metal "mother" disc (like the one shown at the top of this article). These mother discs are then coated and electroplated in order to make "stamper" discs, which are a negative impression of the record, just like the original metal master disc. However, the stampers are also plated with a layer of chromium, which strengthens them enough to be used to press the shellac records that are retailed to the public. The metal stampers are mounted in pressing machines, where they mold a glob of heated bakelite/shellac mixture into the final two-sided disc record.
Most music enthusiasts would assume that when a record is no longer being manufactured, a metal mother disc or a metal stamper would be filed away in the company vault as part of an archival system designed to preserve the company's entire catalog of recorded sound. So, if a researcher needed to look up information about a particular recording (such as how many takes were recorded and mastered) all they would need to do is make a visit to the company record vaults. Likewise, if a recording was to be reissued, the process would be no more difficult than recovering the metal parts from the vault.
Unfortunately, this is usually not the case.
