At the time of "Metallica" recording, the band's songs were written mainly by frontman James Hetfield and drummer Lars Ulrich, with Hetfield being the lyricist. For instance, Newsted wrote the main riff of "My Friend of Misery", which was originally intended to be an instrumental, one of which had been included on every previous Metallica album. The songs were written in two months in mid-1990; the ideas for some of them were originated during the Damaged Justice Tour. Metallica was impressed with Bob Rock's production work on Mötley Crüe's "Dr. Feelgood" (1989) and decided to hire him to work on their album. Initially, the band members were not interested in having Rock producing the album as well, but changed their minds. Ulrich said, "We felt that we still had our best record in us and Bob Rock could help us make it".