A virtuoso is a performer with exceptional skills, both technical and expresssive.
The term comes from the Italian virtù which means virtue, quality.
Initially it was used to indicate many types of qualities, both technical and intellectual. More and more the term has been used with reference to the technical skills, sometime even with pejorative meaning, with reference to mere exhibition of technical ability.
The term virtuoso was used for composers performers such as
Bach
on the organ,
Mozart
and
Beethoven
on the piano,
Carl Stamitz
on the viola,
Paganini
on violin and viola, just to name a few.
Famous viola virtuoso performers were
Lionel Tertis
and William Primrose.