24 Etudes-Caprices Op. 41 by Delphin Alard (1815-1888) are excellent study material. Alard, the violin teacher of Sasasate, composed these studies in the 24 keys. Due to their musical variety, melodic beauty and cantabile voice leading, they are much more than 'technical studies'; they might be described as 'character pieces' in the best sense. The studies meet the two demands principally made on this genre: to both cover specifically certain technical tasks and be appealing as a music piece so that the musician likes to play them.