Massaging up, or away from the string, results in the pin unbending back towards the string, lowering NSL Tension.
Considering that our goal is to keep the NSL Tension high, this would seem like a bad idea.
However, there are situations where this may be done without too much negative effect, with the benefit being that we can arrive at the target pitch with less pin manipulation. This would save time, and be appropriate if we could keep the string stable.
Massaging, or bending, the pin produces no twist. So, the only effect on NSL tension we need to consider is bending/unbending.
Keeping in mind that we want the unbending of the pin to make or keep the NSL tension high, we can massage up (bend pin away from the string) if the following conditions are met. (If these conditions are met, the NSL will remain high):
1) NSL tension needs to be at or near the top of the tension band.
2) Desired pitch change needs to be very small.
We need to keep the force very, very light on the hammer because the bending is followed by unbending. A large force creates a lot of bending followed by a lot of unbending which will loosen to NSL too much. If we are at or near the top of the tension band, this light force will result in the tiniest of bending away from the string raising pitch right away, followed by the tiniest of unbending toward the string, resulting in the tiniest of drop in NSL tension.
But this tiny bending will only result in a tiny pitch change if the NSL is already at or near the top of the tension band before massaging. A good test is that the pitch changes right away.
3) We need a long NSL
(UPDATE: This technique can also work on short NSL if conditions 1 and 2 are met.
Even with this tiny unbending, we can end up with a substantial drop in NSL tension if the NSL is short.(Hooke's Law - Short NSL are very sensitive to any pin movement)
Not if the needed force to change pitch was small enough.
A long NSL reduces the effect of the tiny unbending on the NSL tension and that keeps it high.
True, which means this technique with long NSL can work with slightly larger pitch raise bending.
The following video describes this in more detail with examples at the piano.
NOTE: At 2:04 I talk about the 3rd criteria of having a long NSL. We have updated this procedure to not require the long NSL. I.e. this technique works on short NSL if criteria 1 and 2 are met (i.e. We only need a tiny pitch change. If the tiny massage = a tiny pitch change, this works). In fact, it is very powerful on short NSL because the massage needed to get a pitch change is even less.
Ignore the situation at 4:00. That failed because I started from too low a pitch.
