In the music industry, the A&R personnel is

Question $2$ options:

someone who works in the studio, making hundreds of important decisions about the balance between voice and instruments.

someone who decides which instruments to use to accompany a song, what key it should be in$,$ how many times it should be repeated, and a host of other details.

the person who seeks out performers, often visiting nightclubs and rehearsals to hear new groups.

responsible for all of the above.