To some extent. But that was still before young people started being in integrated groups.Yes. But stations in Flint would have played R & B to an integrated audience in the early 60's, because those artists and groups were performing in and around the Detroit area.
At my high school in the Cleveland area there were no Blacks at all. But right across the street, I was the only white guy at a Black r&b station, WJMO.
No, the Top 40 stations in the later 50's and well into the 60's until Motown came on the scene did not play crossover music. WJMO, the r&b top 40 station, did the job well and Blacks listened to it.I would imagine they were played on Top 40 stations in the Cleveland area also. That is R & B music, which only a decade earlier, would have been considered exclusive to only a Black audience. That's part of the social change. It's bigger than just "flower power" songs.
Same in Miami with both WQAM and WFUN. The Black music was on the r&b station.