Every summer for 75 years, young conductors and musicians from all over the world have made their way to the quiet Maine town of Hancock to study somewhere special: the Pierre Monteux School & Music Festival. Rural Maine often feels like it is way off the beaten track. But for aspiring conductors, the Monteux School is the right place to be. “This place means so much to me,” Tiffany Lu, the conducting associate at the Monteux School who spent four years there as a camper, said this week.