Dénes Koromzay was a founding member of the Hungarian String Quartet. He thus became associated strongly with the music of Béla Bartók throughout his career, which concluded with a peaceful and productive period of residency on the lovely campus of the University of Colorado in Boulder.
Koromzay did his studies at the Franz Liszt Academy in Budapest, where the composer Bartók was on faculty. Koromzay had begun his musical training on violin, but he took on the viola seat in a new string quartet that was forming, which would evolve into the Hungarian String Quartet in 1935. The importance of this ensemble to the Hungarian music scene cannot be underemphasized, and the year of its formation often shows up in timelines of Hungarian history. He remained a member of this quartet until it disbanded in 1972, by which time the ensemble had relocated to the United States, forever realigning geographical priorities for classical ensemble home bases. When the Hungarian String Quartet was initially formed, it drew praise for its performances of Beethoven, but the extremely close association between Bartók and the ensemble's leader, violinist Zoltán Székely, quickly upped the Bartók quotient. The violist was the only member of the original formation to stay with the Hungarian String Quartet until it broke up. He also undertook a career as a freelance soloist from time to time, appearing as a featured artist with orchestras as well as doing studio recordings, including the Miklós Rózsa soundtrack for the 1959 Hollywood blockbuster Ben Hur.
Koromzay's move to Boulder, a college town nestled in the foot of the Rocky Mountains, came about in 1962 while the quartet was in a campus residency there. The group undertook several special programs during this time, attracting sell-out crowds including many students and even younger members of the community. It was a period when the general public's interest in music was expanding well beyond the confines of the pop mentality, and Koromzay took it to heart and put down new roots in Boulder. In the '70s he left for the Midwest and the New Hungarian Quartet, a group in residence at Oberlin Conservatory in Ohio. He then returned to Boulder in 1980 to teach viola and coach chamber music at the university. On visits to Hungary in the early '80s, he met the members of the Takács Quartet, leading to a collaboration. Perhaps hoping to lure more great classical music talent from Budapest to Boulder, he organized a period of residence at the University of Colorado for the Takács Quartet in 1982. He retired from the school in 1996.