High Quality Content by WIKIPEDIA articles! Michael Andrew "Duff" McKagan (born February 5, 1964) is an American musician and writer. He is best known for his twelve-year tenure as the bassist of the hard rock band Guns N` Roses, with whom he achieved worldwide success in the late 1980s and early 1990s. During his later years with the band, he released a solo album, Believe in Me (1993), and formed the short-lived supergroup Neurotic Outsiders.