Possible Clues:

• Saintly patron of church, perhaps, installing European organ
• Large gland
• New, simple key in parts given to piano and organ
• Organ pipe player on endless groove
• Location of the islets of Langerhans
• London saint protecting key insulin producer
• Gland aiding digestion
• Sweetbread
• Organ pipe player's unfinished line
• Large gland behind the stomach