And other vocalists reached a larger audience than any jazz musician could. they flourished not as singers in big bands (as in the swing era) but instead as solo attractions leading their own groups. for jazz musicians who wanted to reach this mainstream audience, the most successful avenue was a musical style called soul jazz.

The answer to this question is:

Explanation:

Ray Charles pioneered soul music during the 1950s for the combination of blues, rhythm and blues and gospel style within the music he recorded for the Atlantic label.

Ray Charles was known in jazz scene at first but his success was bigger than any big band could have, because of that he started to mix his music with gospel and blues and those mixes end up in soul jazz.