Books 1 and 2 contain 57 solos and 67 etudes for the string class, and are written in unison format for Violin, Viola, Cello, and String Bass. These supplements feature exercises designed to reinforce technical development, and to also provide material for musical growth and enrichment.

Featured composers include Bach, Brahms, Dancla, Dotzauer, Grieg, Haydn, Kummer, Lee, Rebikoff, Telemann, Werner, Wohlfahrt and more.