Harrison 's inspiration came from the out-of-copyright Oh Happy Day .
Although Harrison 's inspiration came from the out-of-copyright `` Oh Happy Day '' , `` My Sweet Lord '' was at the centre of a heavily publicised plagiarism suit due to its similarity to the Ronnie Mack song `` He 's So Fine '' , a 1963 hit for the New York girl group The Chiffons .
My Sweet Lord