which reached No. 3 in the US and sold more than a million copies, and the album Who Loves You sold more than 1 million copies. Their next single "December 1963 (Oh, What a Night)" topped the charts in both Britain and the US in early 1976, becoming the group's first US No. 1 since 1967. A remixed version was a hit again in 1994 and its total of 54 weeks in charts gives it the longest tenure of any song on the Billboard Hot 100. By the time of The Doobie Brothers 1976 album Takin' It to the Streets, founding member Tom Johnston had effectively left the band and he was replaced by former Steely Dan session man Michael McDonald, whose distinctive voice helped to propel the group to even greater success. The new album sold strongly, reaching No. 8 in the US, and the title track reached No. 13 on the Billboard Hot 100, becoming a perennial on radio playlists. Warner Bros. also released the massively successful Best of the Doobies (1976), which has become one of the biggest-selling albums of all time and is currently accredited at 10x Platinum status. 1978's Minute by Minute marked the peak of their career—both the album and its lead single "What A Fool Believes" went to No. 1 in the US and the album's title track also made the US Top 20, although it was their last album with founding drummer John Hartman and long-serving guitarist Jeff "Skunk" Baxter. During the late 1970s, Warner Bros.' reputation as an "artists first" label was challenged by a bitter and long-running dispute with Frank Zappa. In 1976, Zappa's relationship with manager Herb Cohen ended in litigation. For Zoot Allures, Zappa took his own copy of the master directly to Warner Bros. Records, who agreed to release the album, therefore bypassing Cohen and DiscReet. However, Warner Bros. changed their position following legal action from Cohen. Zappa was then obligated to deliver four more albums to Warner Bros. for release on DiscReet. Zappa sequenced a double live album and three studio albums, but Warner Bros. objected to some or all of these recordings and refused to reimburse Zappa for production costs, as required by the DiscReet distribution contract. Zappa then re-edited the material into a 4-LP set called Läther (pronounced 'leather'), made a deal with Phonogram, and scheduled the release of Läther for Halloween 1977. However,