Maybe I took to little time and effort to put my thougts clearly...
- What I wrote about squezing into octaves was obviously not about instrument compass or sticking with whole acompaniment througout a song within two octaves. It was about building harmonies (plus melody) over more than 2-3 octaves AT ONCE. We play concertinas with 6 or 8 fingers, pianists can use 10 fingers (I personally can span on almost 4 octaves ona piano, benefit of long fingers), accordinists have registers and multiple voices. At least on a Hayden, it is difficult to add notes to triads (e.g. you can build a major chord with the root strenghted by repeating it an octave lower (4 fingers) but it is extremely hard to do the same with minor chord). Only few finger configurations that allow simultanous play over full compass make sense musically and are comfortable enough to be put into practical use (another example: even on 64 button Hayden one cannot use all available chords in some edge keys, because it is hard to jump the whole keyboard just for one note...)
- Range is continuous of course, but only biggest duets have sides and overlap large enough to think about hands independently and not bother about incorporating accompaniment into melody line or vice-versa and enable using all the fingers at once, like on the piano.
- Many concertinas are baffled, it is more of a personal choice really, I wouldn't say it is hamstringing...
- On Rock and Punk music - I had a solo accompaniment or a guitar+concertina campfire duo in mind, not the fully blown band with bass and percussion with each instrument playing it's sole role. And you seem to agree on the matter, that it is hard to play convincing rock on a concertina. But it is perfectly playable on an accordion, because of multiple voices and better ballance between LH and RH side resulting in richer sound and more "power" of music played. You can imitate that on a concertina, but playing it in a "bandonion like" octave manner, thus dropping halve of your compass - it sound absolutely awfull if you are forced to drop a bass note or canot play arpeggio on just one chord of the whole song, because you're forced to switch sides on the melody. And it is perfectly possible to be your own "percussion" with a duet concertina, it just makes playing in more than 2 octaves at once extremely difficult, with one hand being permanently occupied by rythm and requires big instrument to be able to separate hands completely. And that is what I said earlier.
There is nothing to "sorry" about, we just disagree or misunderstand each other and that is perfectly fine with me. It is obvious, that I speak out only my personal approach and thoughts, not universal "revelations". Try to ask for clarification next time, I will gladly response.
[edited for misspelings]
Edited by Łukasz Martynowicz, 08 October 2013 - 06:12 PM.