Possible Clues:

• Vocaphone
• Set back a fraction of a pound, invested in wood wind instrument of sorts
• Instrument honored in a Beaufort, South Carolina, museum
• Instrument for the musically inept, maybe
• Very easy instrument to play
• Simple instrument
• Agreed to go round Australia with a back-up instrument
• Jug band wind instrument
• Instrument often made of plastic
• Instrument unlikely to be heard at Carnegie Hall