Yes Feynman was a musician; he was also an artist.

While at Los Alamos, Feynman began to play the drums. He had no formal training, did not know rhythms or how to read music. He just played for himself. He started off on a set that he found at the boys' school that had been located at Los Alamos. Later he bought his own. He continued to play the drums after he left Los Alamos. Sometime later he received some training on how to play the bongos from an actual percussionist.

While at Caltech, Feynman was introduced to a group of drummers from the Belgian Congo; he befriended the leader and ended up getting some lessons from him. Later still, Feynman and Ralph Leighton began to play the bongos together. At one point Feynman was asked to perform in the Caltech production of Guys and Dolls, there was one catch though, they gave him sheet music for the part, but he didn't know how to read music. Luckily his friend Ralph Leighton helped him out.

The performance went very well and, so well in fact that Feynman impressed a local ballet director. The director wanted to make a ballet with only drums as an accompaniment, and she wanted Feynman to be playing the drums. He agreed, on one condition, that Ralph Leighton would play with him.

So Feynman and Ralph played for a ballet. The ballet did well. The director even entered the ballet in an international contest. It made it all the way to the final round, in Paris, where it lost to a Latvian group. All in all, though, they did not do too badly.

As I said before, Feynman was also an artist. He painted a bit, but mainly he drew.

Feynman had an artist friend, Jirayr Zorthian, who he would always get into arguments with over art and science. Feynman eventually realized the reason they argued so much was because he knew nothing about art whereas Jirayr knew nothing about science. So they agreed for each to teach the other about his field. Feynman would teach Jirayr about science and Jirayr would teach Feynman about art.

So Feynman learned to draw. He later took lessons from the International Correspondence School and Pasadena Art Museum. He continued to draw over the years, and even put some of his work in a small art exhibit at Caltech. Much to Feynman's surprise, someone wanted to buy some of his work. The drawing was called "The Magnetic Field of the Sun." He enjoyed seeing people getting pleasure from his art, so he continued to sell his drawings. He did not sell them under his own name though, he sold them under the name "Au Fait" (french for "it's done").