One of the boys was taught to play the banjo.(passive voice)
Somebody taught one of the boys to play the banjo. (active voice)
Other Phrases:
Somebody showed one of the boys how to play the banjo.
One of the boys was shown how to play the banjo.
Somebody instructed one of the boys in the art of banjo-playing.
One of the boys was instructed in the art of banjo-playing.
Somebody gave one of the boys banjo lessons.
One of the boys was given banjo lessons.