I've always started my pieces with the bellows completely closed to give me the maximum amount of air on the pull for the first phrase or bars.
I was reading Wim Wakker's tutor book for the Jackie last night and he suggests keeping an inverted V shape by having the front of the bellows closed and fanning out from the back.
Up to now I've just been pulling out and pushing in without too much "curve" but I have to admit Wim's method does seem to give me more control.
I'd like to have other people's opinion on this - both on the starting position and the general shape of the bellows when playing.
Starting position:
I like to start with my bellows approximately half (between 1/3 and 2/3) open. This allows me to start either pulling or pushing. Which direction I start in seems to depend on how I feel at the moment; it isn't even always the same for any particular tune.
Note: I rarely compress or extend my bellows to anything near its full extent. Changing bellows direction is one of many techniques to control phrasing, and it's important to keep enough "slack" to avoid being forced to change direction at an awkward moment.
Belows shape:
I try to keep my bellows more or less "straight", i.e., with the ends parallel. I find that this gives me the greatest overall control.
With my Wheatstone treble I just tried what you quote Wim's tutor as saying, and it confirms what I already knew... that such fanning reduces both the length and volume of bellows I have to work with, and thus it reduces my options for control. (It's been some years since I played a Jackie, but I don't recall a difference in that respect.)
On the other hand, Danny Chapman (ratface here on concertina.net; ProfRat on YouTube) plays superbly, and he uses fanning as a means of opening and closing the bellows, using a strap to keep the bottom of the bellows closed as the pivot of the fan.
Another major difference between Danny and myself is that he always plays seated, with the concertina supported by a leg, while I mostly play with the concertina suspended, even when I'm seated (and even when it's my bass English).
In general:
- Everything you do interacts with everything else. E.g., how far should your thumbs extend into the loops? People differ. What should you do with your little fingers? People differ. If you play while standing, how high and at what angle should you hold the concertina? People differ. Above we started of with differences of opinion regarding fanning the bellows. Different individuals' hands and bodies have different sizes, shapes, and strengths, and this can affect what combinations of techniques work best for each. The most important thing, in my opinion, is that you experiment with various combinations of techniques to find what works for you. And every few months, repeat the experimentation, as your abilities may change with practice.
- I believe another important principle is that one should be flexible, not rigid. Note my use of the words "approximately" and "more or less" above. Variations -- from tiny to large -- in angle, position, tension, etc. work to reduce overall stress and increase stamina by allowing one group of muscles to relax while others take up the burden. Even if that's only for a fraction of a second, it helps, and many individual fractions of a second can have a cumulative effect. I'm constantly making such adjustments (mostly unconsciously, these days), and as a result I can play for long periods without fatigue or pain, even while standing and holding up a bass concertina.