The band began tracking their new album at Little Mountain Sound Studios in Vancouver with producer Mike Stone. By early 1986, much of the record had been recorded. When it came time for Coverdale to record his vocals though, he noticed his voice was unusually nasal and off-pitch. After consulting several specialists, it was revealed that Coverdale had contracted a severe sinus infection. After receiving some antibiotics, Coverdale flew to Compass Point Studios in the Bahamas to resume recording. However, the infection resurfaced which caused Coverdale's septum to collapse. He required surgery, followed by a six month rehabilitation period. John Sykes disputes this and maintains that Coverdale was just suffering from "nerves", and that he used "every excuse possible" not to record his vocals. After recovering from surgery, Coverdale, by his own account, did develop a "mental block" that prevented him from singing. After some failed sessions with Ron Nevison, he was finally able to record his vocals with producer Keith Olsen. By late 1986, much of the record had been finished. Keyboards were provided by Don Airey and Bill Cuomo, while Adrian Vandenberg was brought in to do some guitar overdubs. Additional guitars were also provided by Dann Huff.