Mechanical differences between outside and inside string changes

Indeed, that is one part of the story for me. The other aspect I noticed is that, in outside changes, I get close to the “correct string” with the pick having low/zero velocity. So it feels easy to set it in motion again with a little push without it going in the wrong place.

In contrast, in the inside change the pick is already travelling fast when approaching the new string to be played, so that even small adjustments seem to result in big changes in the pick trajectory, and this gives me a feeling of having somehow less control. To summarize, controlling the deceleration of the pick seems more challenging than controlling its acceleration, if that makes sense.

To me, the difference between the two becomes particularly obvious with large string skips. What about you @Troy, do you start feeling some kind of inside/outside difference when you have to skip multiple strings?

This is an interesting point, and I agree with you that it is in principle possible to reduce the difference in feel, particularly across small distances (not sure about the big string skips as above). The “descending inside” change feels quite easy for me, for example (e.g. in the Gilbert descending 6s lick).

More generally, in “odd notes per string” scale playing, the many discussions we had made me realise that I can reduce the inside/outside difference by limiting the amount of forearm rotation, ideally going “wrist only”. But I know this must not be a general law, as you seem to do pretty much everything with any of the available mechanics!

1 Like

I know what you’re getting at. I think this is a physics question which maybe you can help us answer. An outside string change plays the first note, and in continuing that motion, accelerates and travels far and fast to get to the new string. Then it stops, changes direction, and hits the second note with a normal level of attack. An inside string change is the reverse. It plays the note on the first string with a normal level of attack, and then travels far and fast and hits the second note with no change in direction. So it can feel like you’re slamming into the second note faster then you would like, because you have a running start, so to speak.

So if inside string changes can feel like you’re killing the second note with too much velocity, why don’t outside string changes feel like you’re killing the first note with too much velocity? Is it because you’re close to it and are haven’t reached max velocity yet? So in other words, is pickstroke velocity increasing as the distance increases? Or is there a curve to its velocity? And can that curve be controlled so that even on large inside changes, you’re not slamming the second note with big attack?

Personally I will say that on large inside string changes, I feel like there is a way I slow down to reduce the “running start” effect on the second note. At least that’s what it feels like. I think to know for sure we’d have to film people who are really good at this to see what their velocity curve looks like. It may be that different motion mechanics behave differently, so that people who find inside string changes less “slammy” are actually doing something different to smooth out the velocity curve.

That’s my guess anyway.

1 Like

And yes to the “control” issue, I call this the “foul shot problem”. Like in basketball, when you take a foul shot, if you try to aim at the basket with a low trajectory, you’re trying to get the ball into what looks like a flattened oval. It’s an aiming problem and it’s hard to exactly hit that oval from a distance. So the best foul shot form is to go with a high arc and come straight down, so the target is more circular.

Aiming at the target string from far away and low is like trying to hit the flat oval from the foul line. Players with more vertical movement, like Gypsy jazz players, have less of an issue because they’re coming down more vertical on the target string. Tiny differences in aim don’t affect them as much, because the whole side of the pick is presented to the string. They can be off by a little and still contact pretty squarely.

That being said, when you look at players like Joscho in slow motion, his attack is pretty consistent. He’s hitting the strings with a similar minimal amount of pick all the time. So it’s not like he’s really making use of the larger margin of error. As in this clip:

https://troygrady.com/interviews/joscho-stephan/clips/chromatic-asc/

Very consistent. Joscho’s angle of approach aka “pickslanting motion” is similar to Albert Lee’s, about 35 degrees or so. The most extreme motion slant is Marty Friedman, regularly approaching about 60 degrees. Look at how far away he is:

And here’s the attack:

Even with that kind of attack distance, when this is your motion trajectory, how can you miss?

2 Likes

It’s possible that there’s a difference of velocity if you use the forearm vs if you are doing more of a wrist motion. btw @tommo : you discussed that in your other thread, but from a different perspective.

Now It might be just me, but the use of the forearm here tends to give more of a slam, or ‘kick’ to the downstroke, whereas wrist-only is smoother. Its possible that both motion are not the same velocity-wise. Both can be turned to advantage depending on how you want to sound. A bit of forearm can provide an accent // wrist-only is more fluid. YMMV and again it’s what I feel myself, having encountered that issue when working on rolls lately.

1 Like

There’s a percentage of us, where doing ‘outside’ picking actually feels like we are going against our normal picking inertia… and ‘inside’ picking goes with it. (were in the bizarro world). It’s definitely down to how we generate our picking and our tracking. I don’t have the foggiest idea of the specifics of it all.

I think the trick is actually to get to a point of ‘equillibrium’. Where you feel that neither inside or outside feels like you are going either ‘towards’ or ‘against’ the inertia of the pick… they basically feel the same. I’ve made progress on towards that… and they almost feel the same now… but it’s still not quite there yet.

For sure. When a player comments that either inside or outside picking feels harder, I have a feeling that something is simply not right with their motion. When the motion is correct, there is little difference, especially across small distances like adjacent strings.

However the issue here isn’t whether one is easier or harder, per se. It’s that the “attack phase” of an inside pickstroke simply starts farther away than the attack of an outside string change. Even for someone who perceives no difference in difficulty, there is the unavoidable physics of starting a pickstroke from farther way and getting faster / hitting harder as a result. And the question is, is it necessarily true that such pickstrokes will hit harder, especially as distances get bigger. Or is there a way to equalize this?

I see what your saying.

I guess it depends how we are switching directions, and this might be related to how isolated your tracking and picking are.

If I am doing string alternating skipping 2 strings… I do it in a fairly isolated way… so that my arm does almost all the traveling between the two points… and basically stops moving at the time when my picking motion hits the strings. But again… to do this… I have to really fine-tune the mechanics/inertia of everything… so that’s where I have to get that whole ‘equilbrium’ state. Again… Im still not there… but getting there.

Yes, but if the arm motion and picking motion overlap at all, then the velocity of the pick is the velocity of the arm plus the picking motion. If I’m driving in a car 60 miles per hour in a car and I let a ball drop from my hand out the window, it still goes 60 miles per hour even if I don’t throw it at all. So to avoid the slamming, then no matter what joint is moving, the whole apparatus has to slow down a lot before the pickstroke starts.

Objectively, just looking at what players do, I’m not so sure this really happens. It may just be that these situations involve fast pickstrokes, and maybe you just compensate with a looser grip or something.

Yes, the car/arm has to stop completely for it to work ideally.

Conversely… if I wait too long before picking… my arm will already be traveling away from the string… and I will barely hit the string (or miss it entirely). I did fall into that trap for a short time with my inside picking at high speeds.

Again… it’s equilibrium. Getting everything just right.

I’m sure there are plenty of ways to skin a cat here. Also, there may be those who in use the picking-slamming to help in reversing their tracking momentum. This will definitely result in a hard smack on the string, which would be a combination of the tracking inertia with the picking inertia.

Seems like grip strength, picking depth, and transverse picking angle* would all be useful for this. Volume doesn’t come from how fast you strike the string, but how far you drag it from equilibrium before you let it go.

I personally find grip strength to have a large impact on volume and expressiveness (though I can imagine it’s hard to measure on video), and adjust it semi-consciously when I play. I tend to give a separate squeeze for each pickstroke, instead of continuous pressure, and I’m curious what others do. It reminds me of drawing. The way to draw darker lines is not to push harder against the paper, but to squeeze the pencil harder.

*The deviation from perpendicularity between pick path and string. Equivalent to altitude in a polar coordinate system, where the string is the polar axis. I can’t remember if it has a name in a picking context.

Hi Troy, sorry it took me a while to reply. First off I’d say that despite my “fancy degree”, you seem to be always one step ahead in understanding the Physics Of The Guitar!

You raised many interesting/difficult questions, for now I feel I can try to say something about this one:

My starting hypothesis would be that we can’t directly control the speed of the pick, but only its acceleration (or deceleration - i.e. acceleration in the opposite direction). It is also reasonable to assume that there is a max acceleration we can impart (which may vary for each person). So yeah, I’d say that if you start very close to the string, you won’t be able to gain much speed before you hit it. I think this also implies that you will feel more in control of when/where you’ll hit the string (speculation alert).

About controlling the velocity curve, for now I’ll chicken out and say that it is a difficult biomechanics question (is it harder to control acceleration or deceleration? and so on).

I’m still trying to wrap my head around what could be a simple model for this. But broadly speaking, I think we can make the following statement about the sequence of events:

outside picking: accelerate -> hit the string -> decelerate
inside picking: accelerate -> decelerate -> hit the string

Caveat: the deceleration may be omitted and deferred to a rest stroke after hitting the string in the inside picking scenario, e.g. if we are doing DWPS - this would eliminate the need to use a voluntary muscle contraction, and I think it may happen with both Joscho and Marty. However, in TWPS this would not be an option for example in the infamous Petrucci inside picking exercise.

Note: this post was all over the place. But this reflects exactly the situation inside my head re inside/outside picking.

Note2: @blueberrypie , I think the wrist may smoothen things out a bit due to its limited range of motion -> some of the deceleration is provided for free e.g. when you reach the end of your wrist deviation range. Again, kind of speculative!

2 Likes

Maybe… maybe also some thumb/finger flexion can be used for that effect.