Three volumes of etudes that are largely reminiscent of old folk tunes etc. that gradually increase in difficulty whilst alternating between treble clef, old notation bass clef and new notation bass clef - which is great! The etudes in Volume 1 (50 etudes) obviously start quite simply with an accessible range of between a 5th and an octave in each etude, relatively simple key signatures with few accidentals, and reasonable time signatures and rhythmic patterns. Volume 2 (51 etudes) extends the range out and uses more difficult keys, before Volume 3 (51 etudes) takes it up another level with slightly more complex keys and more creative time signatures being used. The metronome markings added to this final volume are largely responsible for the added difficulty. All the etudes in these volumes are quite short, the longest being a single page in length.