English composer Ralph Vaughan Williams（1872-1958）, an important nationalism composer in early 20th century, and American composer John Williams（1932- ）, a famous film scores composer in the modern age, two composers from early and late 20th century, both coincidentally wrote their own tuba concerto using their respective specialized composition techniques. Amongst the two, Vaughan Williams happens to be the first tuba concerto composer in music history.
This dissertation consists of four chapters. The first chapter discusses research motive and methodology. The second and third chapters analyze the biographies, backgrounds as composers, structures of compositions, and performance techniques of Ralph Vaughan Williams and John Williams respectively. The final chapter summarizes main points in the dissertation and also brings them to a conclusion.
