Oorspronklik: Scale Skills, Level 6. Eleven appropriately graded levels ensure steady progress as pianists advance in their study of technic.
Vertaling: Skaal Vaardighede, Vlak 6. Keith Snell. Piano Metode bladmusiek. Piano Solo bladmusiek. Vir klavier. Ingenieurswese. Graad 6. Musiek boek.