Isn't tonality key relationships, and in a classical sense, movement towards the dominant (or another related key)? Is this what atonality cannot possibly do if there is no tonic key?
The basic principle of tonal melody and harmony is, that the chords and lines are based on a diatonic scale, which may change in piece of course. I doubt that you need a tonica/dominant relations, to get a tonal (or better say: diatonic) feeling. Debussy never wrote atonal, but he didn't care much about cadenza progressions.Atonal means for me:a) the notes don't have a melodical, but sort of paint spot functionb) consonant chords/figures are avoided as far as possiblec) perhaps even more important than the pitches: the rhythm is as unregular as possible
You should start listening to Dallapiccola. His music is atonal, melodic and often consonant.
Twelve-tone is atonal right?