Klengel Daily Exercises (Tagliche Ubungen) Vol. 1
$28.45
Not to be confused with the book of Technical Exercises, this is actually a series of three books. Volume I focuses on the left hand, Volume II deals with the bow arm and wrist, and Volume III moves into thumb position. The first half of Vol. I consists of finger agility exercises, noodley things; the second half is all double stops.
