That year the songs from Rodgers and Hammerstein's Oklahoma!, performed by the show's cast, were released on a multi-record 78-RPM album by American Decca.
Another such example is Ethel Merman, who recorded virtually all of the songs that she made famous, even when there was no original Broadway cast album of a smash hit that she had starred in, as is the case with Girl Crazy, Panama Hattie, and Anything Goes.
)[1] David Hummel, the author of “The Collector’s Guide to the American Musical Theatre” (Scarecrow Press, 1984) was the first person to come up with the term “studio cast” in lists he was making of Broadway recordings.
One such example is the aforementioned Of Thee I Sing, which was recorded on CD with its original orchestrations and vocal arrangements for the first time in 1987, featuring a cast headed by Larry Kert and Maureen McGovern.
Some record the entire group at the same time, as would be played in a live performance, though this can cause some instruments to be picked up on the microphones of others, which can complicate mixing: partition screens are available to counter this.
In the previous example, the bass guitar part that was recorded first might just be a scratch track, to help the drummer get a feel of where emphasis and space in the song is.