Possible Clues:

• Shark sound in ''Jaws''
• Rear neighbour that makes parping noises
• Key instrument in the ''Jaws'' soundtrack
• Massive horn
• Source of low notes
• Instrument for serving up in cocoa butter
• VAT on article? Blow me!
• Instrument featured in a Ralph Vaughan Williams concerto
• 'Tubby the --', a 1945 song by Paul Tripp and George Kleinsinger
• Shark's sound in the ''Jaws'' score