Related Clues:

• Third of a triad
• Interoffice memo, maybe
• Piano key
• Business card number
• Do, re, or mi
• Send by phone
• Student's permission slip
• ""Name That Tune" clue
• A flat one may evoke a wince
• Thank-you item
• Do or sol, e.g.
• Call attention to
• B flat, e.g.
• Half, quarter or eighth follower
• Symphonic piece?