On many DP Mk II songs Roger's bass line is a driving force. Many bass players would play a simple, repetitive 8th notes on DP songs, but not Roger. For example, Roger's bass is all over the place on songs like Highway Star, Pictures of Home, to name a few. Moreover, his Ric tone is to die for. Although I consider Glenn Hughes the voice of rock, DP went downhill in the bass department in Mk III.