What musical instrument did Al Capone play?

Al Capone played the banjo. In fact, he gave Sunday concerts with the inmate band, the Rock Islanders, during his imprisonment at Alcatraz. Prior to prison life, it was also known that Capone played the Mandola.

Many of the Alcatraz prisoners went insane and Capone was possibly one of them. The attempts on his life, the beatings, a stabbing and the prison routine began taking a terrible toll on Capone. After several attempts on his life in the prison yard, he was excused from going outside and later joined the four-man prison band. Gifts to Alcatraz inmates were forbidden, but musical instruments were allowed, so Capone's wife, Mae, sent him a banjo. He would often sit in his cell and play when the other prisoners were outside.

After five years, Capone's mind snapped and there were times when he would refuse to leave his cell and go to the mess hall to eat. Sometimes he would crouch down in the corner of his cell and babble to himself in baby-talk. Another inmate recalled that sometimes Capone would stay in his cell and re-make his bunk over and over again.

He spent the last portion of his time at Alcatraz in the hospital ward. He was being treated for an advanced form of syphilis, which he had been carrying since his youth. He left Alcatraz in 1939.