In multi-track recording, those tracks that are recorded first. In general, the rhythm tracks (guitars, bass, drums, et al).
"The original record I had sent was a very old, scratchy, out of print record that our family listened to years ago every Christmas Eve. It was especially played for my Italian grandmother who died in 1983. I cannot describe the emotion in the room when I played the new CD for my parents, now close to 80 years old. The memories were so good, and ..."