The way I understand how the WPA worked in the arts was to promote public work projects like theater, orchestras, murals and other projects devoted to cultural enrichment of the working class and cultural promotion of public space in general. There were also WPA projects to collect and preserve American folk culture in stories, music, visual arts and design. I think a lot of the collection of all kinds of folk arts and folk music was done under historical perservation projects, mostly run through the Library of Congress.
So where does the mediocre violinist come in? As an currently unemployed wanna be artist, I can imagine working as an employment counselor in the WPA arts section. I'd have him auditioned to see if he was promising enough to join an amatuer orchestra for Sunday concerts in the local park. Maybe join a local poka band where he couldn't do much harm. If not, then how about his knowledge of music? Maybe he might be good as a field collector in white, black, and ethnic folk music.
You folks gotta show some imagination here.
The WPA was run on a pretty ad hoc basis, but there were a lot of smart people involved. In terms of visual artists it launched the careers of Archille Gorky, Wm de Kooning, Jackson Pollock, Ben Shan,...basically most of the post war American art world. It brought some of the Mexican Muralist like Rivera and Orozco here to do public works, hire art workers and teach in workshops. Then there were all those corny looking socialist realist decorations on public buildings to design and build. It really gave a boost to the American Socialist Realist and the Regionalist artists like Thomas Hart Benton for example
CG