Related Clues:

• 'What's the ___?!'
• Pavarotti's range
• Nitty-gritty
• Possible solution
• Voice above bass
• Essential part
• ...
• Caruso, e.g.
• Highest natural adult male voice
• Start of an invention
• Inventor's ''step one''
• Bright one from gray matter
• Sax type
• Main points
• Inventor's start