Attach copies of sheet music to the walls, using a decoupage medium found at any craft store. Options include papering the entire wall, just the bottom half, or randomly layering sheet music to create abstract shapes on different areas of the wall for an artistic look.
Paint the rest of the wall space, if there is any, in the violinist's favorite color. Add a border to separate the sheet music area on the bottom of the wall if necessary.
Frame photographs of famous violinists, such as Nicolo Paganini or Itzhak Perlman. Hang them around the room for inspiration.
Frame personal photographs of the violinist playing at concerts or at home. Hang these up next to the pictures of the famous musicians.
Choose musical fabric prints for the space. For example, in a conservative feeling room choose simple black and white curtains that feature music notes and bars. For a more colorful room, choose prints featuring many musical instruments.
Put models of violins around the room. For example, in a modern whimsical space, hang colorful blowup violins as art on the wall. For a more sophisticated room, bring in statues of famous violinists or composers playing.