casing with a hammer to get it back into tune. This issue also meant that she had to meticulously review each segment for consistency once it had been recorded, because if one line was out of tune the entire section would be ruined. Carlos later recalled that she worked on the recording of the album for eight hours a day, five days a week, for five months, on top of her regular 40-hour-per-week day job at Gotham Studios. Although Switched-On Bach was extremely costly in terms of person-hours expended, her high-quality home studio, her unique proficiency as a programmer and performer on the Moog, and her expert ability as a recording engineer enabled Carlos and her colleagues to record and produce the album completely independently, thereby avoiding the need to use expensive commercial recording studios. As well as the consideration that repeatedly taking the bulky, complex and delicate Moog system to and from a studio for each session would have been almost impossible, given Carlos' own reckoning that the project took over 1100 hours to complete, using commercial studios would have made the recording prohibitively expensive, and would likely have cost upwards of US$100,000 in 1968. By comparison, The Beatles' 1967 album Sgt. Pepper's Lonely Hearts Club Band took over 700 hours to record and cost a reported UK£25,000, or about US$30,000 at the 1968 exchange rate. Additionally, although the recording was extremely labour-intensive, the combination of the Moog and the multitrack recorder gave Carlos and Elkind unprecedented control over every facet of the timbral, expressive and environmental qualities of every single note they recorded, enabling them to create a new level of clarity for each "voice" in the compositions -- a key concern for Elkind, who was critical of what she called the "soggy" audio quality of contemporary classical recordings. Released in October 1968, Switched-On Bach became an unexpected commercial and critical hit, with Glenn Gould, calling it "the album of the decade", and it helped to draw attention to the synthesizer as a genuine musical instrument, although, as biographer Amanda Sewell observes, it is notable that Carlos is not pictured anywhere on the album, and is only mentioned by name (as Walter Carlos) in the rear sleeve notes of the original cover. Newsweek dedicated a full page to Carlos with the caption "Plugging into the Steinway of the future.” It peaked at No. 10 on the US Billboard