for use in small daily doses! I recommend students practice these for 2 minutes in a 60 minute practice session. Do not preserve the percentage: 2 hour practice needs maybe 3 minutes, not 4, if you practice more than two hours, you could spread this out, but I don’t recommend more than 5 minutes at a time for anyone — it’s very finger intensive and you should stop immediately if you develop any pain. These exercises will stretch your fingers; it is very important not to overdo this! Read the story about how composer Robert Schumann crippled his little finger by trying to stretch it and develop finger independence with a mechanical shortcut — well, when searching the internet I found this story was actually not true, but don’t overdo technical exercises anyway! Here is the site Pianist to Pianist with the mythbuster.
The Klengel is difficult to find — one student bought it, but it was volume 1 only, which isa decent scale book, but I have my students buy the much more comprehensive Galamian Scale System, aka my most used tool transcribed for cello by Hans Jørgen-Jensen, so Vol. 1 is totally unnecessary. This link is to the complete; unfortunately for the trees, the first 39 pages are completely unnecessary because the Galamian-Jensen is so much better. This is currently available as used on Amazon.com (click the picture below), so the price and shipping will vary.