### Clue: Stop writer suffering over conductor (10)
### Answer: BARBIROLLI 
 ### Explanation: Definition: conductor
 BAR(to stop;to prevent) + BIRO(a ballpoint pen, the name derived from László Bíró, Hungarian inventor) + **reversal of**(… over, in a down clue) ILL(suffering from, usually, a disease).
Answer: John, British conductor, famous for being conductor of the Hallé Orchestra.