IMO a HUGE contribution in composition as wellThe parameters have to be more clearly defined for any answers to really be meaningful. Are we talking just playing bass or are we taking into account other contributions (fronting the band, stage presence, composition, etc.)? If it's just bass playing then I have a feeling the answers coming from bassists versus those coming from non-bassists are, for the most part, not going to line up.
as a HUGE involvement in defining the style/concept would be required.