Complex sentence: These introductions led to the commission of several works, including "Two by One" (solo violin) for the pre-eminent Russian violinist, Raimundas Katillus, who performed the composer's music at Carnegie Hall.
Split into simpler sentences: These introductions led to the commission of several works, including "Two by One" (solo violin) for the pre-eminent Russian violinist, Raimundas Katillus. Soon after Katillus performed the composer's music at Carnegie Hall.