The clear, graded material in the eight-volume series of exercises is based on relative solmization, and focuses on teaching singing in tune, developing a good ear, and functional thinking. Most of the examples in the booklets are taken from the musical literature, rather than being invented for teaching purposes, so students deepen their knowledge through genuine music.

The eight booklets contain a total of 100 lessons. Szőnyi recommends the first 30 lessons before starting to learn an instrument, lessons 31-69 can provide the material for primary and secondary music education, and the additional lessons are for students of music in institutions of higher education. The author encourages the creative use of the booklets (the teacher can invent new exercises), but at the same time recommends that the carefully structured pedagogical order of the lessons remain unchanged.

The practice booklets are supplemented by methodological publications, which, by describing how to use the exercises in teaching, actually provide a summary of the theory and practice of the Kodály method, based on actual classroom experience. The highly successful teacher's books have been translated into many languages.