all members were unavailable, so Bowie traveled to New York City for further recruitment. Pianist Mike Garson, saxophonist David Sanborn and percussionist Pablo Rosario were retained from the Diamond Dogs Tour, while guitarist Earl Slick was replaced by Alomar. At Alomar's suggestion, Bowie hired former drummer of Sly and the Family Stone, Andy Newmark to replace Tony Newman and bassist Willie Weeks of the Isley Brothers to replace Herbie Flowers. When Bowie informed Visconti in London of Weeks' involvement, Visconti left for New York immediately, saying: "I'm a bass player myself, and [Weeks] was my idol". Cherry, Alomar's wife Robin Clark and then-unknown singer Luther Vandross performed backing vocals for the sessions. Philadelphia sessions Demo work began at Sigma Sound on 8August 1974, but official work commenced three days later upon Visconti's arrival. Before Philadelphia, Bowie had spent most of his recording career in Britain, where recording methods were different from those in the States. At Olympic and Trident Studios in Britain, engineers applied equalisers and reverb as they were recording, so these effects were heard upon playback. At Sigma Sound, however, the engineers applied zero effects when recording, applying these during the mixing stage instead. As a result, Bowie was initially confounded when hearing the tapes back, as according to biographer Chris O'Leary, he "hadn't heard his 'naked' voice on tape in years." "Take It in Right", now retitled "Can You Hear Me?", was one of the first songs recorded for the album, on 13August. The sessions moved rapidly, only taking two weeks to complete. It was agreed early on to record as much of the album as possible live, with the full band playing together, including Bowie's vocals, as a single continuous take for each song. According to Visconti, the album contains "about 85% 'live' David Bowie". During this time, Bowie's cocaine addiction heightened at a rapid pace, and as a result, he stayed up day and night recording while the band slept. According to Pegg, an anonymous musician recalled Bowie "waiting several hours for coke to be delivered from New York and he wouldn't perform until it came." His cocaine use affected his voice, creating what Bowie himself called "a real raspy sound" that prevented him from singing higher notes. Nevertheless, Bowie believed the album contained the highest notes he ever sang on record. The sessions at Sigma Sound were very productive, resulting in numerous outtakes, including