Jan Koetsier (1911-2006) was a Dutch composer and conductor, known for his contributions to classical music, particularly in the 20th century. He was born in Amsterdam and studied at the Amsterdam Conservatory. Koetsier's genre primarily encompassed orchestral and chamber music, with a strong focus on neo-classical styles, blending traditional forms with modern influences. Notable works include his "Symphony No. 1," "Symphony No. 2," and various chamber pieces, including sonatas and concertos for different instruments. His "Concerto for Tuba and Orchestra" is particularly recognized for showcasing the tuba as a solo instrument. Koetsier had a significant impact on music education, serving as a professor at several institutions and influencing a generation of musicians. He was also active in promoting Dutch music internationally, helping to elevate the profile of Dutch composers. His work as a conductor and his engagement with the music community contributed to the dissemination and appreciation of classical music in the Netherlands and beyond. His legacy continues through recordings of his compositions and his influence on contemporary Dutch composers.