The Würzburg composer Bertold Hummel wrote his four-movement Metamorphosen in 1969 and dedicated it to the guitarist Siegfried Behrend. Hummel does not use the twelve-tone technique in the strict Schoenbergian sense, but more freely, as Alban Berg did. Hummel thus allows himself to restart a row - each movement has its own, related to the others - even before he has used all its notes. Typical of his approach to twelve-tone rows are tone changes, fragmentations and repetitions, resulting in tonality fields. The title Metamorphoses describes a fundamental principle of all composition, indeed of all art in general: that of transformation, of change.

The first movement, Rezitativ, demonstrates a fundamental metamorphosis, so to speak - that of a single tone that is set in motion at the beginning, first charging itself with energy, as it were, in order to then traverse the tonal space. Starting from the note e - because of the tuning, e is the centre of gravity of the guitar sound - the recitative gradually conquers the entire tonal space, so that after about a third, with the prominent high notes e flat'' and d flat'', the twelve notes of an octave are played at least once and the basic features of the row are established. The row is then tested piece by piece for its playing possibilities. The last three bars are a quintessence. Below the e' (the note to which the first string is tuned) the entire row runs. This once again presents the entire range of notes available to the composer.

The performance instruction "burlesque" in the second movement, the Intermezzo, not only tells the performer how to play this piece, it also characterises the three-part piece (A-B-A') itself. It is burlesque in at least four ways: the wide interval leaps of the row, the cuckoo call (notes 6, 7, 8 and 4 of the inversion row), the twisted row before the final chord and the fact that the row mostly appears as an inversion, i.e. upside down.

The third movement, Melancolia, is reminiscent of lute songs. A melody ornamented with scales unfolds over row tones drawn together to form chords.

The finale, a motoric guttural piece, is characterised by an eight-note row. The main interval is the second. Hummel forms a kind of pendulum motion out of it through sometimes excessive repetitions, which runs counter to the impulse pushing ahead: The piece treads water, seems to get stuck - and then abruptly releases itself again. The finale reaches its final chord in the same way, in its very own way of travelling. This time the tension is released so suddenly that the row (as an inversion) tumbles headlong down to A, the root note. An A major chord promptly follows: Unbroken tonal splendour - that's Bertold Hummel's little surprise at the good end.

Thomas Wirth (in CD booklet "Metamorphosen - Kurt Hiesl, Gitarre", AHO-Recording 1997)