How do you put a song to play while someone waits on the line?

The Other day i had someone call me, and it wasnt a telemarketer, but she told me to wait because she was getting another call, and while i waited a song played then she hung up with the other person and went back to the line and the song stopped, i have a boost and sprint phone is there any way to play a song while they wait if im on the other line or if i just put it on mute??