[1][2] He was the official translator, into English, of the textbook of the Leningrad Choreographic School (the Vaganova Academy).

[6][7][8] He also danced with the American Ballet Theatre, in numerous summer stock performances of musicals.

[11] In 1967, Barker attended a ballet lesson taught by the Russian ballet master, Alexander Ivanovich Pushkin, where he admitted that watching the class made him want to "learn Russian to speak with him and learn from him how to become a better teacher.

[11] Subsequently, Chujoy put Barker in touch with Natalia Roslavleva, a leading Soviet dance historian, who sent him six lessons of Asaf Messerer.

[11] Barker studied and collaborated for many years with Vera Kostrovitskaya, who was Agrippina Vaganova's assistant.

[14] His grandfather, John William Barker, and namesake, was a prominent citizen in Maywood, Illinois after arriving from England in the 1880s.

Some of his pedagogical students include: Janet L. Springer, Willard Hall, [19] Peggy Willis-Aarnio, Sharon Dante, Howard Epstein, Cathy Longinotti, Lynda Gooding Nelson, Gretchen Warren Ward, and John White.