Difficulty level, roughly compared to ABRSM exam grades. 0 is beginner, 9 is advanced (beyond grade 8).
Contentstaken from the foreword:
As a clarinettist and teacher, I - as well as many other people - have never really felt the necessity to practise or teach etudes very much. It is true that practising Jeanjean etudes helps you to play Debussy, but so does practising Debussy! On the other hand, the practice of scales and arpeggios seems vital to me because this is the ingredient that music is made of; it is - or should be - ear-training at least as much as it is technical practice.
Mechanical exercises are also very useful because they are a condensation of the difficulties we have simply in getting from one note to the other. Playing any instrument is a labour fit for a contortionist. Our fingers are called upon to do all sorts of awkward unnatural things. The only trouble is that the usual exercises - useful though they certainly are - are as sterile as they are painful. We practise them with the puritanical idea that we must take our medicine beaten into us by our stern, disciplinarian teachers. The danger in this is that it insidiously cultivates the idea that on the one hand there is technique and on the other hand, music and seldom do the twain meet. Yet there is nothing more counterproductive and unmusical than drudgery.
I have absolutely no illusions or pretentions about the musical value of the little pieces you will find in this book that are essentially designed to improve your ability to play "finger twisters" and get your technique in shape. I do, however, feel they are useful and what's more, fun, and I definitely feel you should have fun.