After great lengths of cursing the inadequacies of all normal chairs I have yet come across...
I have finally settled on a suitable seat for Stick practice:
The Tama Ergo-Rider, with backrest.
I chose this chair based solely on experience, through experimentation and comparison between different seats.
Here's why this seat rocks:
First, because it doesn't. It's totally solid with no wobbles.
Second, because the backrest is functional -- and this is the crucial part.
The back rest's low-profile leaves plenty of room for my elbows to move around while playing.
The back rest gives support to the lower back, where it feels most ergonomically comfortable.
The back rest can be adjusted to sit very far forward, allowing the Stick to rest between the legs and stand up straight (slightly angled to the left of course)
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Here's why other thrones didn't make the cut:
Office chairs and dining chairs suck. (Greg I don't know how you do it)
Even with no arm rest, the back rest on any normal chair is so big, it always gets in the way of my elbows.
Moreover, a normal chair will have such a big seat, that I have to choose between proper playing posture, and proper back support.
Case in point:
•If I sit back against a normal backrest, the Stick leeeeaans back with me, resulting in a terribly unplayable angle overall.
•If I sit forward, up on the front edge of my seat, I gain proper playing posture but give up my backrest. Eventually, this gets tiring.
•I can compromise by letting the Stick rest off to the side, to the right of my legs. This is okay, but ultimately I find this position to significantly limit my reach on the instrument as well as throwing off my playing posture.
Stick between the legs seems best, and that also requires a low profile from the actual seat you're sitting on. Ergo-rider satisfies here, too.
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The only drawback I find in the Ergo-rider is that, with my moderate stature, the seat itself is a bit higher off the ground than I'd like -- even at its very lowest adjustment setting.
For a drummer, this would be ok. I actually like to sit a bit high at a drumset, so that my knees bend at greater than a 90-degree angle.
But, for the Stick, I would like to have my knees at 90-degrees precisely, so that I could use a lap bar.
With my legs more angled, the lap bar slides forward.
Instead, I wear a belt even for seated play.
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Worth noting, when I perform Stick on stage I prefer to stand nearly 100% of the time.
Some would say that if you stand on stage, you should also stand while you practice.
I disagree, however, because I get tired while standing for practice.
Being on stage (in front of an audience) is usually very energizing for me, so standing feels right. I can move, I can dance.
Practicing, on the other hand, is usually a solitary activity. Without an audience, practice isn't always as "exciting" as performing, but that's part of the game. It's a sacred space for improving my ability.
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With a proper seat such as the Ergo-rider, I am able to find flow in my practice much more easily, which enables me to practice longer and be more creative.