What does music "mastering" mean?

Updated July 31, 2015

If you buy reissue CDs of old music, or if you produce them, you see the marketing phrase "Digitally Remastered".
WRONG.
Ya don't know what mastering means.
So stop filling this society with illiteracy.

The people at Rhino Records explained it very well:
The core of the confusion comes from the base word itself, "master".  In music, a master is a tape that has been prepared to manufacture either a record, cassette, 8-track or CD. Over the past 50-odd years, however, the word "master" has been used to describe a number of different types of tape and as such has become a bit ubiquitous, particularly in advertising copy.
In the simplest scenario, mastering historically meant taking the original tape that was used to record a recording session and then
preparing it by applying various electronic processes (filtering, equalizing, echo, copying, etc.) to the tape. When the processing was completed - that is, when the producer thought he had gotten the best commercial sound possible - that processed copy or original became the "MASTERTAPE" or "master". This was then used to make the metal parts that eventually would "stamp out" 45 RPM (or 78 RPM) singles.

This processing was necessary in the early days, particularly when the record label was small and the recording studio and microphones primitive. The actual tape running during the session - which we refer to as the "SESSION TAPE" - was often out of balance with regard to volume levels, and had to be equalized and compressed to allow for correct cutting of the actual record grooves during manufacture and to compensate for faulty recording technique. It should be mentioned too that even 60 years ago, vocal performances were often brought from poor or mediocre to acceptable by way of electronic tinkering.

As overdubbing came into use in the 1960s, another stage was added to the mastering process. A "basic track" would be recorded first (usually the instrumentals); then, whatever was to be overdubbed (like the lead vocal or a special percussion instrument or sound effect) would be recorded and combined with that basic track tape to make a copy. That copy would
then be processed and become the MASTER TAPE.

When LPs began to flourish in the late '50s and early '60s, another stage was added to the mastering process. Eager to release album product, many labels sought to gather up a number of their previous single releases to form an LP. To do this, they would go back to the MASTER TAPE for the various singles, and copy
each one onto a (watch out!) "master compilation tape". This tape was then copied.. with processing to produce an "album master". Technological development meant more confusion in terminology. As cassettes and 8-track tapes became viable music carriers, special master tapes had to be prepared for each configuration. And what does a record company do in this case - they make another copy, a copy of an "album master" that is then re-sequenced for cassette or 8-track. These copies become "cassette masters' and "8-track masters". Masters, masters, masters.

The real dirty word in all of this is "copy". Every time a tape is copied, the resulting copy "loses" something from the original. It also gains distortion. ... If one company wanted to license a recording from another, they would not receive anything approaching the original SESSION tape; instead, they would receive yet another copy, a copy of a copy in effect. Considering the lack of importance attached to rock'n'roll in general by virtually all labels in the '50s and '60s, this practice of copying tapes ad nauseum coupled with a general sloppiness in tape archiving and the assumption that "one master is as good as another", had led us to the predicament we now find ourselves in when trying to produce quality reissues of this vintage material  ...

When we talk about sloppiness in the record industry, we can go on for days. In the early pre-LP days, labels would often throw out or record over the original SESSION TAPES and just keep the MASTER. Sometimes they would just cut the actual 'take" chosen for mastering from the SESSION TAPE and splice it onto another reel (which leads to another confusing use of terminology ... the "take" chosen as best from a recording session is often called the "master take" or...can you guess...the "master"). Often that small piece of tape would be moved and removed to different album masters as time went on, making their location today nearly impossible to find. Sometimes the basic track can be found, but the overdubs necessary to reproduce the actual record may be lost. ...

"Remastered from the original tapes" sounds wonderful, but it can be misleading. All of the stages mentioned above can be considered "original tapes", and a number of different tapes can be considered the "original masters".


CONCLUSIONS:

So for all you CD issuers, when you copy vinyl records to digital, ya ain't "remastering" nothin.
You are making a copy that is based on the original masters, which is okay in its own way.

As for really remastering from the session tapes, I am not pleased with that. It usually does not sound as good as the original hits masters. To think that you can do a better job than the original people?

There is also the term "remixing". I wonder how much it's being misused. If you are just editing a copy, you sure are not remixing.

Vinyl albums in the digital era:
They tend to be made from the digital masters. Old music is digitized from analog to make a CD. Then the doinks make the vinyl from the digital master instead of the analog. Vinyl buyers get no advantage over the CDs.
If you are wondering ... analog music has all the sound in it, but digital loses much of it. 16-bit (CD) music is limited.
The only hope is 32-bit floating point digital recording. That is not used commercially.