According to Theodosii Spassov own words, two conversations with fellow musicians: one in 2023 in London with Svetlin Roussev and Nayden Todorov, and the second with Mario Hossen were the reason for composing his Concert for kaval, violin and orchestra. “He was moved by my Concerto for Kaval, Clarinet and Orchestra, which I had performed many times with the clarinettists Ilian Iliev, Boyan Ivanov and Borislav Yotsov with various symphony orchestras in Bulgaria,” the author recounts. “It is dedicated to Mario Hossen. The concert is in the classical three-movement cycle. Each movement is in irregular rhythm: the first is in 9/8 (with changing places of the three-time group), the second is in 7/8 (with the three-time group in first time) and the third movement is in 7/8 (with the three-time group in third time). The score is scored in equal time patterns to make it easier for non-Bulgarian orchestras to read. There are sections intended for improvisations on the kaval, written solos and cadenzas for the violin in the third movement.