Possible Clues:

• Play a note and strike a chord?
• Jog memory: what you may have to do to gain admission
• Jog one's memory — as would campanologist?
• Signal pupils to assemble perhaps: sound familiar?
• Take one back, possibly, as may master for servant?
• Do what crier did — sound familiar?
• Make a tinkling noise to serve as a reminder?
• To awaken a memory
• Sound familiar