Possible Clues:

• Key of Mendelssohn's Octet, Op. 20
• Key of Beethoven's ''Eroica Symphony''
• Part of a C minor
• D sharp's alias
• Key of the overture to Mozart's "The Magic Flute"
• Key of the 'Eroica'
• Type of clarinet
• Liszt's 'Concerto No. 1 in --'
• Key of Eroica
• One of the black keys on a piano