How do I locate an old friend?

In October 1905 Satie enrolled in Vincent d'Indy's Schola Cantorum to study classical counterpoint (while still continuing his cabaret work). Most of his friends were as dumbfounded as the professors at the Schola when they heard about his new plan to return to the classrooms (especially as d'Indy was an admiring pupil of Saint-Saëns, not particularly favoured by Satie). As for Satie's motivation for this step, there were probably two main reasons: first, he was tired of being told that the harmonisation of his compositions was erratic (a criticism he could not very well counter while not having completed any studies in music), and secondly, he was developing the idea that one of the most typical characteristics of French music was clarity (which could better be achieved with a good background knowledge of how traditional harmony was perceived). Satie would follow these courses at the Schola, as a respected pupil, for more than five years, receiving a first (intermediate) diploma in 1908.