Possible Clues:

• Serenade accompaniment
• Instrument left with Victorian pick-up
• Stringed instrument shaped like a halved egg
• Vintage Tull out-take reviewed in 'Melody Maker'
• Minstrel's instrument, perhaps
• Balladeer's aid
• Musical instrument producing oddly loud note
• Sir Thomas Wyatt's obeys
• Signora leaves regulations to plucky musical type
• Madrigal accompaniment, perhaps