Possible Clues:

• Me in C minor
• Note in the C minor scale
• Key of Beethoven's "Emperor Concerto"
• Key of the ''Eroica'' symphony
• Only black key in the 21 notes that start at 127 Across
• D sharp
• Key of Liszt's Piano Concerto No. 1
• Key next to D
• Key of Mahler's "Symphony of a Thousand"
• Key of Beethoven's Third