What factors lead to a new professionalization of music production and songwriting in the early 1960s? [Select all that apply]多项选择题

the payola scandal

the need to treat a growing number of artists in a fair and equitable manner, as demand for recorded music declined.

the desire to replicate rock and roll's unprecedented success.

a need for greater industry control following the shock of the grassroots, unpredictable nature of rock and roll