Capitalize, but do not use quotation marks, on descriptive titles for orchestral works: Bach’s Suite No. 1 for Orchestra: Beethoven’s Serenade for Flute, Violin and Viola.
If the instrumentation is not part of the title but is added for explanatory purposes, the names of the instruments are lowercased: Mozart’s Sinfonia Concertante in E Flat Major for violin and viola. If in doubt lowercase the names of instruments.
Use quotation marks for nonmusical terms in a title: Beethoven’s “Eroica” symphony. If the work has a special full title, all of it is quoted: “Symphonie Fantastique,” “Rhapsody in Blue.” In subsequent references lowercase; symphony, concerto, etc.