Possible Clues:

• Historian's musical instrument?
• One takes notes, one plays notes
• Is capable of making notes working in the court
• Part-time judge on about arrangement
• Arrange again to incorporate first of cases for part-time judge
• The one who takes notes and a tubular wind instrument
• Instrument that's used by logger?
• Instrument in song by Queen
• Stenographer's instrument
• Black box, e.g