Quartetto Mosso is comprised of four musicians from the Springfield Symphony Orchestra: Ronald Gorevic, Beth Welty, Delores Thayer, and Yoonhee Ko. In 2023, the four members decided to combine their talents and concentrate on the quartet literature in all its forms, with a focus on female composers and rarely heard masterpieces. Their repertoire spans a wide range, from standard classics through lesser known works and wonderful arrangements of popular music. They bring thoughtful and exciting interpretations to all of their repertoire.

MOSSO stands for Musicians of the Springfield Symphony Orchestra. In music, the term mosso means moving forward or played with motion. The quartet embodies the idea of moving forward by championing works from both the past and present, and bring to light lesser known works of music.

In the orchestra, Ronald Gorevic currently serves as principal violist, Beth Welty serves as principal second violinist, Delores Thayer serves as assistant principal violist, and Yoonhee Ko holds a rotating seat in the cello section.