Many session musicians specialize in playing common rhythm section instruments such as guitar, piano, bass, or drums.
Some have become publicly recognized, such as the Wrecking Crew, the Muscle Shoals Rhythm Section[3] and The Funk Brothers who worked with Motown Records.
In some cases, larger or heavier instruments may be provided by the recording studio, such as a grand piano or Hammond organ and Leslie speaker.
In jazz, rock, and many popular music genres, performers may be expected to read chord charts and improvise accompaniment and solos.
In country music, performers may be expected to read Nashville Number System charts and improvise accompaniment and solos.
Similarly, a bass player asked to improvise a walking bassline in a rockabilly song needs to know the stock lines and cliches used in this genre.
During the 1950s and 1960s, session players were usually active in local recording scenes concentrated in places such as Los Angeles, New York City, Nashville, Memphis, Detroit, and Muscle Shoals.
[5] At the time, multi-tracking equipment, though common, was less elaborate, and instrumental backing tracks were often recorded "hot" with an ensemble playing live in the studio.
[8] In the 1960s, Los Angeles was considered the top recording destination in the United States — consequently studios were constantly booked around the clock, and session time was highly sought after and expensive.