Grapefruit is a collection of event scores, initially written on cards. The book's title comes from the fact that the grapefruit is a hybrid derived from the sweet orange and the pomelo. The book itself is a hybrid, combining literature with painting, music, and performance. In the ‘Biography/Statement’, issued by Yoko Ono in 1966, she writes in the chronology: ‘late adolescence: gave birth to a grapefruit, collected snails, clouds, garbage cans, etc.’ The unusual format (single event scores, each on a separate card) which became a crucial precursor to conceptualism, emerged from the event scores created by artists associated with John Cage's Experimental Music Composition classes at the New School 1957 – 1959. On the recto of the introductory card for the set is a key to the genres of event scores found in Grapefruit: painting (40 cards), poetry (8), music (52), event (42), object (8).