Although there are no standards for discographies, the key elements given for each recording in nearly all discographical listings are the name of the record label, issue number, and program contents; the physical characteristics of the recording itself, such as type, size, the number of channels, playback speed, and type of groove, are also considered important features of true discographies. The complex catalogs that have come to be known as “systematic discographies” include such further details as master numbers (or matrix numbers for the earlier galvano-processed discs); take indicators (or transfer numbers for discs processed from tape sources); the date and location of, and the key participants in the recording session; the date and place of publication, and publisher of the various issues and reissues (with label names and numbers). Before the development of long-playing (LP) recordings, a unique matrix number was etched, embossed, or stamped onto the surfaces of most discs, near or under the label. However, early cylinders often bear no markings, making identification difficult if the recording has been separated from its container. Since it was a common practice for several versions of a performance to be made (in case of mishap, or with many cylinder recordings because producing multiple copies from the same master was difficult), each of the versions (or “takes”) was customarily assigned an additional number or letter, which was placed immediately after the matrix number. The convention of matrix and take numbers was abandoned with tape mastering, in which a fully edited master tape could be developed from all the material recorded during the sessions; successive modifications of a given master tape may be identified on the finished disc by the transfer numbers. (...
