Catherine Urner journeyed to Paris to study with Charles Koechlin after winning a prize for several years' study of music abroad. She studied with him from 1919-1921, when she returned to America and was appointed director of vocal music at Mills College. She continued to compose and give vocal recitals throughout California and made several more trips to Paris where her first string quartet premiered at Salle Pleyel in 1925. Urner arranged for Koechlin to come to the United States to teach a summer course in music at the University of California, Berkeley in 1928, and during this time their affaire became more intense and Koechlin persuaded her to return to France with him. Catherine lived with the Koechlin family until 1933. Koechlin harmonized many of her melodies and they collaborated on symphonic poem, 'The Bride of a God'. The strain of the relationship between Catherine and Charles on the Koechlin family became too great and Catherine returned permanently to the US in 1933. Four years later she married her friend and pupil, the organist Charles Shatto, though this happy union ended in tragedy.