At the age of 19, Graham wrote what is probably his most famous composition, the acoustic guitar solo "Angi" (sometimes spelled "Anji": see below). Colin Harper credits Graham with single-handedly inventing the concept of the folk guitar instrumental. "Angi", named after his then girlfriend, appeared on his debut EP "3/4 AD" in April 1962. The tune spread through a generation of aspiring guitarists, changing its spelling as it went. Before the record was released, Bert Jansch had learnt it from a 1961 tape borrowed from Len Partridge. Jansch included it on his 1965 debut album as "Angie". The spelling "Anji" became the more widely used after it appeared on Simon & Garfunkel's 1966 album "Sounds of Silence". In 1969, the same name for Chicken Shack's "100 Ton Chicken" was used.