The original version was recorded by Captain & Tennille, who worked with Johnston in the early 1970s with the Beach Boys. It appears on their 1975 album Love Will Keep Us Together. The first release of "I Write the Songs" as a single was by teen idol David Cassidy from his 1975 solo album The Higher They Climb, produced by Johnston. Cassidy's version reached number 11 on the UK Singles Chart in August of that year.[6] After Manilow's hit, Johnston recorded the song for his 1977 album Going Public.
Johnston has stated that, for him, the "I" in the song is God,[3] and that songs come from the spirit of creativity in everyone. He has said that the song is not about his Beach Boys bandmate Brian Wilson.[7]
Manilow was initially reluctant to record the song, stating in his autobiography Sweet Life: "The problem with the song was that if you didn't listen carefully to the lyric, you would think that the singer was singing about himself. It could be misinterpreted as a monumental ego trip."[4] After persuasion by Clive Davis, then president of Arista Records, Manilow recorded the song, and his version of "I Write the Songs" was the first single taken from the album Tryin' to Get the Feeling. It first charted on the Billboard Hot 100 on November 15, 1975, reaching the top of the chart nine weeks later, on January 17, 1976. Cash Box said of Manilow's version "Good work Barry" describing the song as "melodic, ballad-like beginning grows into an operatic crescendo, all done in clear production that all age groups will appreciate."[8]Record World called it "an uplifting production number" and "perhaps [Manilow's] strongest offering since 'Mandy.'" [9]