For me, anyway. In my collection of twenty five million music books I came across one called, Frank Simon presents the famous Herman Bellstedt jr. Twelve Famous Technical studies (sic) Cover price is $1.50, so it OLD. It contains, slurring exercises, enharmonic fingering, staccato attacks, chord progressions and chromatics (Allo con fuoco!), Glissandos, Octaves and harmonics, and five more, including something called "Velocity", for a total of twelve. It's all in 14 pages, and some every day turns out to be a great warm up!