The natural horn has a much smaller bore than the typical valved horn, giving it a quieter, brighter tone. In about 1760 the horn player Hampel of Dresden found that its natural tones could be lowered a semitone or whole tone by placing the open hand with closed fingers into the bell. This discovery led to the composition of the most important and beautiful music for the horn, including all the concertos and chamber music by Mozart, Beethoven, and Haydn. Brahms himself may have played the instrument, and he called for it in his first three symphonies and the horn trio. The Quartet is the largest and most difficult in a series of pieces I have composed for the natural horn. These pieces refuse to view it as a historical instrument. Rather, they extend its playing technique into twentieth century idioms and forge for it a new role that is thoroughly contemporary.