Raphaël Pidoux, Gioffredo Cappa Saluzzo, 1680

Popper's message is clear and powerful, and there is nothing to add to it. We can only endeavour to respect his generous character as well as his pieces of advice which are still as pertinent today as they have always been in spite of the fact that, for commercial reasons, some publishers have produced modified editions.

Study n°1 :
In spite of the fact that, in the time of Duport, cellists used to play strong beats up bow, , Popper suggests to do the opposite in the 1st Study. This provides an impetus which will foster an independence of the two hands.
The left hand can then take advantage of the lightness of the bow to focus on the shiftings implying to be practised in double strings, which means a minute practising of the thumb positions in semi tones.

Study n°40
Owing to the purity of the harmonic notes, the bow has to be intelligent and accurate :producing a good harmonic sound generally implies a short attack of the note, as well as as a fast relaxed movement of the bow. This study allows us to practise the art art of rubatos, since it proves almost impossible to keep the tempo in virtuoso passages which have to remain articulate. Note that harmonic notes often imply a correct tension of the left hand, since the latter is in contact with the string but not with the finger bow