Horatio Parker was an American composer of the so-called "Second New
England School" of composition (actually German-trained).  His best-known
composition is probably his oratorio _Hora Novissima_.  He taught at Yale
(he was known to be quite strict and conservative), and was department
chair for many years.  No doubt his most famous students were Roger
Sessions and Charles Ives.  Ives and Parker had little in common musically,
and there was much resentment.  Likely Parker was a good candidate for
Ives's appellation of "Rollo."

One anecdote tells of a visit to one of Parker's classes by composer George
Chadwick.  Coincidentally, Parker was in the process of critiquing one of
Ives's songs, saying there were "too many keys in the middle." Chadwick
looked at it and said, "In its way it's almost as good as Brahms." And,
turning to Chadwick, "That's as good a song as you could write!"

Dick Hihn