 Dorsey, who had once composed for and played piano behind blues giants Tampa Red, Ma Rainey and Bessie Smith, worked hard to develop this new music, organizing an annual convention for gospel artists, touring with Martin to sell sheet music and gradually overcoming the resistance of more conservative churches to what many of them considered sinful, worldly music.Combining the sixteen bar structure and blues modes and rhythms with religious lyrics, Dorsey's compositions opened up possibilities for innovative singers such as Sister Rosetta Tharpe to apply their very individual talents to his songs, while inspiring church members to "shout" — either to call out catch phrases or to add musical lines of their own in response to the singers.This looser style affected other black religious musical styles as well.