Related Clues:

• Adjusted the pitch of, as a piano
• Pleasant way to play
• Not off-key
• Adjusted a baby grand
• Like a purring Jaguar
• Sung correctly
• Musically correct
• Ignored, with 'out'
• Harmonically perfect
• Au courant, with "in"
• Like a good singer
• Sharpened, say?
• Made less sharp
• Musically precise
• No longer flat