Complex sentence: The latter may be because this is the first album not to feature a keyboardist in Osbourne's backup band, and guitarist Zakk Wylde filled the spot for the album, and sometimes chose to add a keyboard solo to a song rather than a guitar solo.
Split into simpler sentences: The latter may be because this is the first album not to feature a keyboardist in Osbourne's backup band. Guitarist Zakk Wylde filled the spot for the album, and sometimes chose to add a keyboard solo to a song rather than a guitar solo.