From the middle period of Attila Bozay, there are traces of a frequently used ten-tone tonality type – from Op. 31. Csongor and Tünde - what became very precious for the composer in his whole life. Ha called it decatony.
Bozay’s decatony is a ten-tone tonality, which leaves out two tones from the chromatic scale in which tones are tritone intervals apart. Therefore this tonality contains two chromatic pentachord, which is transposed by a tritone. This decatony can use six different transpositions of its pitch-class set.
Bozay’s decatony is similar – at least in its tones – with Olivier Messiaen’s 7th modus.
Bozay used twelve-tone and eleven-tone sets as well.
He used different reduced forms of his decatony. These reduced nine-note forms leave out the middle note in one of the chromatic five-note clusters. It means that two possible nine-tone reduced forms are available in a decatony set. He used the possibilities of these tonalities in his compositions and created an eight-tone reduced form that leaves out both middle notes in the chromatic pentatone. This eight-tone module is similar to Bartók’s 1:2 distance model in Lendvai’s studies, Messiaen’s second modus, or Stravinsky’s two Dorian tetrachords in tritone distance.