Related Clues:

• Instrument that's difficult to tune
• Certain reed instrument
• Woodwind able to provide an orchestra's tuning note
• Soloist in Schubert's Ninth Symphony
• The duck in Prokofiev's 'Peter and the Wolf'
• Sarrusophone relative
• "O" in old radio lingo
• Instrument with a bell
• Double-reeded instrument
• It's an honour to possess old instrument
• Tramp 'eard in the wind?
• It gives the orchestra an A
• Instrument Martin's left is a trombone
• O, there's only half an aeroplane, blow it!
• Music producer in love with broker, oddly