Hi,
One of my goals here is to show we have lots of compositional resources at hand. Of course, many of you know it, and use them. Sometimes I write very short pieces to "test" the effect of one or other harmonic combination. Later on, if I like the results, I take it for composing something more expressive.
In this case, I try to mix the eclesiastic modes (dorian, lydian, eolian, etc...).
When we use two modes at a time = bimodality
When we use two tonal centers at a time = bitonality
When we use two modes and two tonal centers at a time = bimodality + bitonality, which is what I did here.
The piano is perfect for this purpose: one hand one mode in a tonal center, the other hand in different ones.
Of course, every combination is different. I wouldn't say there are better ones, worse ones. Unavoidably, there are clashes here and there, but the task of a composer (even the amateur, like me) is to control them to create relax-tension.
Please, these pieces are not intended to be "beatifullly expressive". They are meant to show the effect of the combination. I wrote them in a few minutes.
Study I = D dorian + C lydian
Study II = D locrian + G mixolydian
Study III = G dorian + A eolian
I always encourage, particularly to amateur composers, to read about this stuff, to explore a little. The musical universe is endless, and it is there to expand our expressive possibilities.