Related Clues:

• Important piece in an arch
• It's the foundation for crucial one at end of street
• Kop supporter?
• Locking piece for arch
• Vital principle of part of piano sound
• Central part of arch
• What tops an arch
• Piece at the top of a masonry arch
• Vital support for sound of part of piano
• Central policy; arch top
• Summit block in an arch
• Two piano features on which all else depends
• Cops perhaps find openers on pitch
• The chief element in the sound of a piano?
• Chief brick in an arch