Possible Clues:

• Ma makes a living with it
• It has a long neck
• You might take a bow for this
• Musical instrument like large violin held between knees
• Stradivari creation
• Instrument like large violin held between knees
• Music-maker initially operating with subversive group
• For the prisoner, nothiing with strings attached
• Musical instrument like large violin held between legs
• Part for five Beethoven sonatas