Thoughts on how to use the disambiguation comment for recordings.
For live recordings, there is a specific guideline:
"live, YYYY-MM-DD: Venue, City, State/Province, Country"
It is often useful to disambiguate studio recordings as well. A proposed format:
"studio, YYYY-MM-DD: Label [ Matrix] [, Additional Info]"
Each segment should be regarded as optional.
Label: The record label for which this was recorded. This is useful when the same artist has recorded for multiple labels; for an artist like Jimmie Rodgers, who only ever recorded for one label, this can be omitted. Examples:
- Johnny Cash recorded for Columbia until 1986, then signed with Mercury and re-recorded many of his Columbia songs.
- During the 1920s and early 1930s, Duke Ellington alternated recording for as many as four labels. Though originally released under various aliases, many of these sides have later been reissued under Ellington's own name.
Matrix: Sometimes also called "master number", the matrix number is a unique (with rare exceptions) identifier assigned in the studio to a specific recording of a specific performance. Multiple takes of the same song on the same day will each have a unique matrix number. Generally, each label has its own format so it makes sense to include the label and matrix number together.
Additional Info: Other distinguishing criteria that help tell one similar recording from another. This may include:
- Recording session: The album or other project for which this was recorded. Helpful for identifying alternate takes added to expanded re-releases of an album.
- "master take" or "alternate take": The "master take" is the one originally chosen for release; an "alternate take" is any other performance of the same work from the same session that was not initially released. Expanded re-releases or compilations often include alternate takes labeled as such.
- First release date: Alternate takes are often released only many years after recording. If known, the first release date can rule out their appearance on any released earlier than that.
- Descriptive information such as unique solos or vocal nuances that identify a specific version. See below for examples.
Louis Armstrong and His Orchestra: Star Dust (studio, 1931-11-04: Okeh matrix W 405061-1, "oh memory" take)
Jimmie Rodgers: Whippin' That Old T.B. (initially released take, 1933; has fiddle solo) vs Whippin’ That Old T.B. (alternate take, first released 1991; has guitar solo) (I need to update these to follow the format)
"broadcast, YYYY-MM-DD: Studio/location [, Additional Info]"