"Apostrophe (')" is an instrumental featuring bassist Jack Bruce and session drummer Jim Gordon, who was on tour with Zappa's band at the time of the session in November 1972. Bruce is credited on the album cover with bass guitar and co-writing the title song. However, in an interview for Polish rock magazine "Tylko Rock" he said that he had not played any bass guitar parts or done any co-writing on "Apostrophe (')", only the cello intro. He reminisced, "So I turned up in a NY studio with my cello, I'm listening to music, pretty awful, and just don't know what to do with myself, and Frank [Zappa says to me: "Listen, I would like you to play a sound, like this... whaaaaaang!!!" So I did what he asked me to do. Whaaaaaang!!! That was all. That was my input to Frank Zappa's most popular record! " Bruce had studied the instrument at the Royal Scottish Academy of Music and Drama and performed with it on some of his other recordings.