Neatly interwoven with his career as a composer was Chadwick's chief employment as an educator, which lasted for about fifty years. He trained numerous students who themselves became composers and teachers. In this way, he had an exuberant influence on American musical life, far beyond his own generation. Besides Horatio Parker and Arthur Whiting, his most well-known students, in alphabetical order, are: Frederick S. Converse (1871-1940), Mabel W. Daniels, Wallace Goodrich, Henry Kimball Hadley, Edward Burlingame Hill, Helen Francis Hood (1863-1949), Margaret Ruthven Lang (1867-1972), Daniel Gregory Mason (1873-1953), Arthur Nevin, Harry Newton Redman (1869-1958), Anna Priscilla Risher (1875-1946), Leroy Robertson (1896-1971), Arthur Shepherd (1880-1958), and William Grant Still (1895-1878). This impressive list shows that Chadwick's classes were open to every talented person, without restrictions of gender or ethnicity.1 Some of his students continued their studies with Rheinberger in Munich, especially those from the earlier years, such as Parker, Whiting, Goodrich, and Daniels, whereas a later student, such as Hadley, went to Vienna, where he studied composition and conducting. Chadwick also sent conservatory students from other classes to teachers in Europe. One of them was the Venezuelan pianist Teresa Carreño, whom Chadwick had adored as “the most interesting and the most inspiring” artist since the 1870s and who taught in Berlin after 1902 for several years.

Chadwick's most frequently published work was his Harmony book, which appeared in more than seventy editions. He, like most American music scholars, had studied with Ernst Friedrich Richter's Manual of Harmony, published in Leipzig in 1853 and translated into English in 1864, which had several subsequent editions. Certainly the reflection of what he had come across in Leipzig inspired him to create a textbook of his own, adapted for studies in America. In particular, the numerous publications of Jadassohn must have been known to him, and maybe inspired him, or at least have made him think about shaping a text-book of his own.

However, the most sustainable achievement in the field of education that has to be credited to Chadwick was the development of the New England Conservatory into “a national institution of the highest standing.”