Rautavaara's Etudes are presented as a series of interval studies, the various intervals providing a distinct colouring to the music. According to the composer's wife Sini Rautavaara: "Each interval seems to want to behave in a certain way, to adopt a certain value, to create a certain ambience: the brilliant, egoistical 'Thirds', the 'Sevenths' vainly seeking rest, the anxiously vague 'Tritones'; the 'Fourths' like forces of nature; the expressive 'Seconds', and the airily rhythmic 'Fifths'.