However, during the 20th century, the instrument was revitalized thanks to the work of a number of violists and composers, which led to the commission and composition of many more viola concertos, expanding the repertoire significantly.
Early examples of violas taking solo roles in orchestral settings include Johann Sebastian Bach's Brandenburg Concerto No.
A number of violists and composers are credited with revitalizing the viola concerto and expanding its repertoire, with much of it centralized in Britain in the early 1900s.
Tertis also commissioned pieces such as Ralph Vaughan Williams' Flos Campi and Gustav Holst's Lyric Movement for Viola and Small Orchestra, in addition to gaining permission to transpose works for the viola, such as Edward Elgar's Cello Concerto and Frederick Delius's Caprice and Elegy for Cello and Orchestra.
[1] William Primrose was also an important figure in establishing the role of the viola as a soloist, having a number of concertos dedicated to him by composers like Quincy Porter and Darius Milhaud.