The scarcity of practice collections devoted to a speciality defined problem of technique has often been deplored by both teachers and pupils. However, Masters of piano playing have written such collections whose number is countless and which deal with difficulties of all kinds. Unfortunately, they are spread over a very large number of music books. The volumes referred to above countain a sufficiently great number to allow counteracting this dispersion. Each collection embraces only the studies intended solely for one of the manifold particularities of piano technique. Carefully revised and judiciously chosen, they will help the pupil to correct efficiently, certain weaknesses in his technique and thus improve systematically, his piano playing as a whole.