Matrix numbers

Matrix numbers

From Wikipedia, the free encyclopedia

Matrix numbers.

Matrix numbers are alphanumeric codes (and on occasion, other symbols) stamped or hand written (or a combination of the two) into the run-out groove area of a gramophone record. This is the non-grooved area between the end of the final band on a record’s side and the label, also known as the run-off groove area, end-groove area, matrix area, or “dead wax”.

Industry usage

Matrix numbers are intended for the internal use of the record manufacturing plant, but they are also studied and documented by record collectors, as they can sometimes provide useful information about the edition of the record.

There are two parts of the matrix number to be considered: the main number, which is usually printed on the label as well, and extra information which can include a cut or take number. Matrix numbers can refer to any of these elements, or all of them combined. The inscription area may also contain record plant codes or logos, the initials or signature of the disc cutting engineer, and cutting or copyright dates, among other things.

The matrix number printed on the label should not be confused with the catalogue number, which is usually in larger type, and will typically be the same number on both sides of the record. Matrix numbers will be different on each side, and are sometimes printed upside down on the label to prevent them from being mistaken for the catalogue number.

The purpose of the main number is to assign a filing number to the stamper, and to ensure each side receives the proper label, by visually comparing the number on the label to the inscribed number.

The most important part of the extra information is usually the cut number, which is a suffix to the main number. For example, matrix number 12345 is seen on a label, but examination of the run-out groove area reveals number 12345–3, which indicates this is the third cut of this side. It is not unusual to find records with a different cut number on each side.

Sides are recut for various reasons. Record stampers can only be used to make so many copies before they become worn, and a new cut is required. (As of the early 1980s, this was no longer true. Changes to master disc manufacturing methods, including the DMM or Direct Metal Mastering system, made it possible to make many copies of a master cut non-destructively, so a recut was no longer necessary when the plate used for pressing became worn.) Stampers can also become damaged from handling. Recuts can also be made when there is a problem with the previous cut, for example, a technical fault or improper banding (the visual separation between songs). When a new cut is made, several copies called test pressings are made for technicians (and, for a new record, the producer and the recording artist) to review the cut, and determine if it should be accepted or rejected. If it is rejected, another cut must be made.

More reasons for multiple cuts: If a record is pressed at more than one factory, as can be the case when a popular release is issued by a major record company with factories in more than one city, each factory may make its own master cut. If a record is issued internationally, each country typically cuts its own masters. If a record is re-issued by a different company, or by the same company under a different catalogue number, the record is usually recut, although there are occasions where the previous cut is reused and the new number is added to the inscriptions in the run-out area, sometimes with the previous number scratched out.


Records with one song per side, particularly 7-inch 45 rpm and 10-inch or 12-inch 78 rpm records, are often found with non-consecutive matrix numbers on each side, and the “hit” side or “side one” may not necessarily be the lower number. This indicates that the numbers were probably assigned at the time the songs were recorded. If there is a significant gap between the two numbers, the songs were probably not recorded at the same session. If the numbers appear to be from completely different sequences, or have a different format or number of digits, this can indicate that the numbers were assigned by the recording studio, and the two sides were recorded at different studios. When record historian Brian Rust researched his discography books on early recordings, he was able to determine the studio and approximate recording date of certain songs from matrix numbers by comparing them to other numbers in the sequence.

78 rpm records

In the days of 78 rpm records, before recording tape was commonly used (up to approx. 1950), audio recordings were cut directly to disc. The recording studio would assign a number to the song to be recorded, which would become the main part of the matrix number, and several takes would be made, with the take number inscribed in the matrix area. Only one take would be selected for issue in most cases, but there are occasions where alternate takes were issued as well, possibly by accident. Frequently, the record label on an alternate take is identical to the label for the more common take, as it only shows the “main” matrix number for the song without the take number.

Alternate takes are of interest to collectors, particularly if the music is jazz. Since jazz is often partially improvised, two takes can contain significant differences, and a comparison of two takes can reveal which portions of the music were pre-determined, and which were improvised or variable. Also, when two takes are released, one is usually much more common than the other, and the less common take can become a valuable record to collectors.

Take numbers on Victor Records can usually be found to the left at the label, i.e. the “9 o’clock” position.

When looking for matrix information on 78 rpm records, care should be taken to examine the label area as well, as some numbers may be coded underneath the label, and are viewable as indentations.


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