Born in Copenhagen, Denmark, as a young boy Berthelsen immigrated to the United States with his mother and six brothers. Although he was always drawn to the visual arts, it was music that he studied initially, with such success that in 1901 Berthelsen was awarded a full scholarship for vocal training at the Chicago Music College. Upon graduation in 1905, he toured the United States and Canada performing in various operas and musicals for approximately five years. In 1910 he joined the faculty of the Chicago Music College, and taught voice there for three years. It was during this time that Berthelsen was encouraged to take up painting by fellow Scandinavian artist Svend Svendsen.
In 1913, he moved to become the head of the voice department at Indianapolis Conservatory of Music. While in Indiana, he started painting with Wayman Adams—who had studied with William Merritt Chase and Robert Henri in Europe—whose influence and instruction helped Berthelsen develop his unique, atmospheric pastel style.
Berthelsen moved to New York City in 1920, but it was not until after the stock market crash of 1929 that he relinquished his role as a voice coach to the stars of Broadway and the Metropolitan Opera. Prior to the crash he had painted pastel cityscapes, which were well received by the American Watercolor Society, and in an effort to bring his family through the Great Depression, he turned to oil painting. Over the next decades, Berthelsen’s reputation flourished with his Impressionist renderings of iconic symbols of New York City.
The artist was a member of the Salmagundi Club, the American Watercolor Society, and the Allied Artists of America, New York. He exhibited widely and was the recipient of
Berthelsen’s works may be found in such notable private collections and institutions as the Butler Institute of American Art, Youngstown, OH; the Hickory Museum of Art, Hickory, NC; Indiana State Museum, Indianapolis, IN; Indiana University; the Dailey Family Memorial Collection of Paintings, Bloomington, IN; the Sheldon Swope Art Museum, Terre Haute, IN; the Museum of Texas Tech University, Lubbock, TX; and the Wake Forest University, Winston-Salem, NC.
Peter Hastings Falk, Who Was Who in American Art: 1564-1975 (Madison, CT: Soundview Press, 1999)
Ray Davenport, Davenport’s Art Reference (Gordon’s Art Reference Inc., 2004)