Possible Clues:

• A white key is not artificial
• A turn is normal over a half-century
• Reason for death when not suspicious
• (In music) neither sharp nor flat
• Afro
• Turning brown, Russian river, as is to be expected
• Fuel from underground
• Gifted individual scoring mark
• Illegitimate person born with a particular skill
• Ultra-jumpy after an upset, which is to be expected