 The group was formed in 1967 by Emerson , Lee Jackson , David O 'List and Ian Hague to back soul singer P. P. Arnold . After replacing Hague with Brian Davison , the group set out on their own , quickly developing a strong live following . The group 's sound was centred on Emerson 's Hammond organ showmanship and abuse of the instrument , and their radical rearrangements of classical music themes and Bob Dylan songs . 
