What a wonderful site! Perhaps the best, I have seen so far, about the individual artist.

Gustav Klimt (1862-1918) started as an academic painter. He studied fresco, mosaics and other traditional art techniques during his years at the university. He had received several public art commissions, but his style and vision were to progressive for dominating Victorian morals in Vienna at that time. Congress conducted a poll and Klimt was incriminated for "pornography" and "excessive" perversion. He was forced to reject the career in the public arts and, became Klimt... Klimt was an active member/founder of the "Secession" - Association of Austrian Visual Artists.
"Our Secession in not a confrontation of young artists against the old ones, but a struggle to revalue artists against hawkers
that make believe they are artists and have commercial interest to prevent art from flourishing" wrote Hermann Bahr in the declaration of the Secessionists in 1897.
However, later in his career he began to doubt the Secession, harmony of the arts had proven (for Klimt) to be a utopia. He began to see the concept as old-fashioned and abandoned the group.

In a way the transition from classic to modern is "recorded" in Klimt's work.
I think that would be a great starting point and visual/historical reference to the for the discussion in "Modern Art versus Classic Art".