In order to demonstrate that Wings was not merely a McCartney showcase, Denny Laine sang lead vocals on several songs, including "Go Now", reprising his vocal from the Moody Blues' 1965 hit, and Simon & Garfunkel's song "Richard Cory". Jimmy McCulloch also sang lead, on his "Venus and Mars" composition "Medicine Jar". Of particular interest to fans and music critics, McCartney decided to perform five of his songs from the Beatles, thereby overcoming an earlier disinclination to do any at all. Performances of "Yesterday" and "The Long and Winding Road" used muted horn arrangements in place of their original strings. In the case of the latter song, the new arrangement emphasised McCartney's objections to the version released on "Let It Be" in 1970, where, according to McCartney, American producer Phil Spector had added orchestral and choral parts to the Beatles' 1969 recording without his approval.