SUMMARY
In the analysis of Classical music and partly of Baroque and Romantic music as well – in all the latter's late and belated forms – the harmonics, that is to say the traditional theory of the functional progressions of chords, are a helpful basis for the explanation of harmonies. Functional harmony is, however, only one of the principles of Osterc's compositional technique. Therefore only some passages of his music can be explained through this, and therefore, naturally, there are only a few compositions which can be placed within traditional tonality. There are more, in which one can speak of a tonal centre. After his studies in Prague atonality comes to the fore but not always consistently, because Osterc combines it with tonal principles as well as with series which are never exploited dodecaphonically. The combining of different principles is characteristic of Osterc on the whole, i. e. the combination of traditional with new, new with traditional, a synthesis of the expected and unexpected. The analysis of individual harmonies reveals a whole kaleidoscope of chords, typical of much of the music of the first half of the 20th century: more or less complete chords by thirds – from triads to thirteenths, by fourths, added-note chords, chords by seconds, polychords and compound harmonies. As, in practice, vertical principles not only interchange with horizontal ones but are also interwoven with them, some aspects of these relations are dealt with in the article; especially considering the fact that for Osterc horizontal thinking is more important and therefore more typical. This does not mean, of course, that the sonority which thus results is accidental. The analysis of some passages of his music shows that his instrumental lines are consciously formed into harmonies he heard in his search for new, as yet unexploited sounds.