Possible Clues:

• Instrument like large violin
• Bowed musical instrument
• Instrument firm's internal measure
• Yo-Yo Ma's prop
• It's bigger than a viola, but smaller than a double bass
• For the prisoner to get around with strings attached
• Where there's a prisoner that gets nothing with strings attached
• Jacqueline Du Pre's instrument
• String-section member
• Part of prison circle in large-scale fiddle