Bowie contributed backing vocals, keyboards, and guitar to Reed's 1972 solo breakthrough "Transformer", co-producing the album with Mick Ronson. The following year, Bowie co-produced and mixed The Stooges album "Raw Power" alongside Iggy Pop. His own "Aladdin Sane" (1973) topped the UK chart, his first number-one album. Described by Bowie as "Ziggy goes to America", it contained songs he wrote while travelling to and across the US during the earlier part of the Ziggy tour, which now continued to Japan to promote the new album. "Aladdin Sane" spawned the UK top five singles "The Jean Genie" and "Drive-In Saturday".