How were adventure playground of the 1960s different from playgrounds of the 1920w

What role do background vocalists play? a. they provide additional support to the main vocalist and other members of a music group during recording sessions and live events. b. they perform as part of orchestras working for music theaters. c. they mix different songs or music scores and present a unique blend of music to an audience. d. they assemble and organize musical compositions according to their clients’ requirements.