in the recording of the album at Trident Studios, London, serving as the co-producer and primary session musician (contributing guitar, piano, recorder and backing vocals), as well as arranger, contributing the string arrangement for "Perfect Day". Reed lauded Ronson's contribution in the Transformer episode of the documentary series Classic Albums, praising the beauty of his work and keeping down the vocal to highlight the strings. The songs on the album are now among Reed's best-known works, including "Walk on the Wild Side", "Perfect Day" and "Satellite of Love", and the album's commercial success elevated him from cult status to become an international star. Artwork The cover art was from a Mick Rock photograph that inadvertently became over-exposed as he was printing it in the darkroom. Rock noticed the flaw but decided he liked the fortuitous effect enough to submit the image for the album cover. According to Rock, "When I showed Lou the contact sheets, he zeroed in on the transformer shot. I made the print myself – as I usually did in those days. The first test I made fell out of focus in the exposure. Lou loved the result. It took me twelve attempts to reproduce this accident for the final larger print for the album cover". Karl Stoecker (who also shot the first three Roxy Music album covers) took the back cover photo of a woman and a man. The woman is 1960s London supermodel Gala Mitchel. The man is portrayed by Ernie Thormahlen (a friend of Reed). The man appears to have a noticeable erection, although Reed has said this was actually a banana which Thormahlen had stuffed down his jeans before the photo shoot. Release The first single from the album, "Walk on the Wild Side", became an international success, despite its controversial subject matter. The song's lyrics mention transgender issues, sex acts, and drugs, causing it to be edited in some countries and banned in others. It is now generally regarded by fans and critics as Reed's signature tune. "Satellite of Love" was issued as the second single in February 1973. In 2002, a 30th anniversary edition of the album was released; in addition to demos of "Hangin' Round" and "Perfect Day", it includes a hidden track featuring an advert for the album. Following Reed's death in October 2013, digital sales of Transformer, "Walk on the Wild Side", and "Perfect Day" all rose more