H.A. Vandercook composed ten solos that were named for gemstones (pub. Rubank 1938). The format of each solo is the same- a slow theme, a more involved variation, a second theme (trio), and a return to the first variation that ends with a coda. The solos range in difficulty from easy to medium. Some of these videos have tutorial sections and others have important thoughts (like listings of alternate positions) in the descriptions.