Grammy-winning producer Russ Titelman first met Mo Ostin, the legendary executive who ran Reprise and then Warner Records from 1960 to 1994, in the early ’60s when Titelman was still a teenager and freshly signed to Screen Gems-Columbia Music as a songwriter. Eventually, Ostin, who died July 31 at 95, and then head of A&R Lenny Waronker convinced Titelman to come to Warner Records, where he had an extraordinary run as an in-house producer for 25 years, working with such artists as Randy Newman, Eric Clapton, Paul Simon, James Taylor, Steve Winwood, Chaka Khan and so many more. Titelman, whose Grammy wins include record of the year for Winwood’s “Higher Love” (1986) and again for Clapton’s “Tears in Heaven,” as well as album of the year for Clapton’s “Unplugged” (1992), talked with Bill...