Bookends is the fourth studio album by American folk rock duo Simon & Garfunkel. Produced by Paul Simon, Art Garfunkel and Roy Halee, the album was released on April 3, 1968, in the United States by Columbia Records. The duo had risen to fame two years prior with the albums Sounds of Silence and Parsley, Sage, Rosemary and Thyme and the soundtrack album for the 1967 film The Graduate. Bookends is a concept album that explores a life journey from childhood to old age. Side one of the album marks successive stages in life, the theme serving as bookends to the life cycle. Side two largely consists of previously-released singles and of unused material for The Graduate soundtrack. Simon's lyrics concern youth, disillusionment, relationships, old age, and mortality. Much of the material was crafted alongside producer John Simon (no relation), who joined the recording when Paul Simon suffered from writer's block. The album was recorded gradually over the period of a year, with production speeding up around the later months of 1967. Initial sales for Bookends were substantial in the US, and the album produced the number-one single "Mrs. Robinson". The album sold well in the US and in the United Kingdom, where it peaked at number one. Bookends was considered a breakthrough for the duo, placing them on the same level as artists such as Aretha Franklin, The Beatles, Bob Dylan, and The Rolling Stones at the forefront of the cultural movement in the 1960s. The album has continued to receive critical acclaim and is debated by critics as to whether it or Bridge Over Troubled Water is Simon & Garfunkel's best album. Background Simon & Garfunkel first became prominent on American radio in 1965 with their record "The Sound of Silence", which became a hit during a period in which the duo had broken up due to the failure of their debut release, Wednesday Morning, 3 A.M. (1964). Following another release, Sounds of Silence (1965), the duo recorded and released Parsley, Sage, Rosemary and Thyme (1966), which brought new critical and commercial success to the duo. Simon, then 25, felt he had finally "made it" into an upper echelon of rock and roll, while most importantly retaining artistic integrity ("making him spiritually closer to Bob Dylan than to, say, Bobby Darin", wrote biographer Marc Eliot). The duo chose William Morris as their booking agency after a recommendation from