"You don't use a thumb strap? On a single row? That would be challenging. The only way I can think that would work out would be if you used two shoulder straps instead of one. Is that what you do?"
You use a thumb strap ? How do you play that way ? Restrictive.
I use one shoulder strap and press the box against my left knee/leg/thigh. Locks it in place. Thumb against the edge of the fingerboard . Complete and free movement.
I do not find the thumb strap to be restrictive. I can easily position my hand so that 4 fingers can cover 4 buttons on the full range of the keyboard. That includes the "home" position of buttons 5, 6, 7, 8, and also the low note position of buttons 1, 2, 3, 4, and the high note position of buttons 7, 8, 9, 10. I can easily and quickly shift between these three areas.
I suppose that YMMV depending on the size of your hands. Mine are fairly big, so maybe that's why I don't find my hand movements to be unduly restricted by the thumb strap.
Since I always play standing up, it is not an option to brace the accordion with a knee, leg or thigh.
Bohemian, it seems like you hold your accordion like Sharon Shannon, is that correct? You see this approach very often with Irish players.
I have a two row Castagnari and tried it too (for Irish trad), but never really got the hang of it. Maybe my left arm is too short.
Yes, OMG yes I play like Sharron Shannon..
Gag me...
NO.
Sharon Shannnon uses a huge bit of foam on the bass side. plays stepped keyboards, and has talent and skill I will never have.
She plays like no one.
However, I do play like 90% of the Irish players as to position.
Lock the box.
As one very famous Irish B/C player now living in America says..
Get a shot glass of whiskey, put it on the top of the box and play without spilling a drop.
I never play standing up.
I sit and lock the box. One last thing to worry about.