William Primrose CBE was a Scottish violist and teacher. He performed with the London String Quartet from 1930 to 1935. He then joined the NBC Symphony Orchestra where he formed the Primrose Quartet. He performed in various countries around the world as a soloist throughout his career. He also taught at several universities and institutions. He authored several books on viola technique.

The viola ( vee-OH-lə, Italian: [ˈvjɔːla, viˈɔːla]) is a string instrument that is usually bowed. Slightly larger than a violin, it has a lower and deeper sound. Since the 18th century, it has been the middle or alto voice of the violin family, between the violin (which is tuned a perfect fifth higher) and the cello (which is tuned an octave lower). The strings from low to high are typically tuned to C3, G3, D4, and A4.