you would have to have some inhumanly heavy bow pressure for the tuning to change. I mean "inhuman" as in it would require a robot arm to put enough pressure on the bow for that effect to become noticeable.
before you notice a change in tuning from pressure, you would notice a change in tone from the bow being squished against the string. Remember that the bow is horsehair tightened in a wooden frame. And that tension IS finite. if for some reason, you loosen the horsehair in your bow beyond the point where you can tighten it with the mechanism of your bow (it only turns a certain amount), then you would have to have the bow restrung (or re-haired? I'm not sure what you would call it).
I wouldn't worry about it. it's not like a violinist is going to LET the instrument detune simply because the bow pressure is heavier. You would only ever get the effect on an open string, and it would be microscopic. (but for what it's worth, it would be higher, as you're adding extra tension to the string)
remember that the finger is also pressing down on the string. and the string player automatically adjusts for any micro-tuning differences.
I think Raymond didn't mean that the tuning changes (i.e., the pitch of the open strings), but rather that the pitch of a tone slightly fluctuates when the bow pressure changes. In that case, his question is more: does the tone go flat or sharp when using heavy bow pressure in comparison to light bowing (all other things being equal).
My guess is that the tone would go slightly up, but it's a tough choice: the pressure stretches the string, which lowers pitch, but also increases tension, which increases it. I guess tension wins.
Anyway, would it make a noticeable change? Can't you get the same from turning var 1 & 2 up a little bit?
You are right. I should have used the word "pitch".
But thanks for the replies. I knew that the variations should be very subtle, but one thing of recognizing a "computer recorded" string section is the lack of just that bit of variation.
The same book "MIDI orchestration" also recommended using a "mirrored" extra library like some synth sounds (Roland) to play along and to be tuned/higher pitched a bit different to get that "natural" hearing and feeling. I tried to do that, but eventually skipped it because of phasing problems (and those synth instruments not always keep track of the min/max range of the instruments).
you both realize that as the player adds weight to the bow arm, which theoretically alters the pitch of the string by adding tension to it, the OTHER hand is adjusting its position on the string to compensate, yes?
this is a non-issue for a string player.
only a poor player will have intonation problems that vary by bow weight.
If the player's bow arm adds pressure, yes, the pitch would normally go up ever so slightly (it's a microscopic amount.. the bow CAN'T exert that much pressure without damage).
and here's where the "however" is quite important:
the other hand isn't just sitting there.
The left hand moves. It doesn't clamp down on the fingerboard without moving.
There is the normal vibrato of the left hand.
There is the normal adjustment for pitch variation.
It is, in all, a dynamic process that requires fine adjustments on the part of both hands.
I would argue that what makes a recording with MIDI sound like a recording with MIDI rather than a "live" recording, has nothing to do with this type of micro-tuning non-issue.
It has to do with the fact that a string section is made up of individuals that are spaced across a 3-dimensional surface (well, the are spaced 2-dimensionally, really, but let's say some are taller, and some are shorter). The living, breathing string section is dynamic and uneven. Not because of the effect of bow pressure on a string, but because human players are imperfect. If one player in a 12-violinist section plays out of tune, well you hear 1 player out of 12.
A MIDI recording (a sample, if you will) is a single point-source. If it plays out of tune, it ALL plays out of tune.
Unless you use 12 different sampled violins, played by different performers, to create your string section, no amount of "tweaking" will add actual realism to the recording. You may as well settle for MIDI's inherent "perfection".
This may be just me -- or rather, just the sample libraries that I have been using (GPO, DDSSA, KH, PS) -- but it seems as if, in some of them (particularly the trem articulations) the sound is scratchier. Is this true in the real world?
Raymond, I didn't want to come across as obstinate or obtuse.
I play a bit of viola (have been taking lessons since last summer), and have of course performed with a lot of string players over the last 40 years.
I just felt that you might be over-thinking this issue.
I think, with a solo instrument, the occasional "out of tune" note adds a certain touch of realism (I think of my latest acquisition: Xsamples Chamber Ensemble sample library.. where at certain speeds, you get little slightly-out-of-tune notes here and there. It adds IMMENSELY to the realism of a recording.)
But with a section, the dynamics of the amount of people involved, the very physical attribute that is a "group of performers playing in unison" changes the rules of the game considerably.
I haven't tried yet, but I suspect that even adding my solo violin with it's occasional wrong notes to a violin section, will not have quite the desired effect. I think the solo instrument will end up sounding like a solo instrument with a backing of uniform section of violins.
When I listen to various recordings done using GPO I find that the solo instruments (other than strings) tend to sound far better than the sectional instruments (the strings). The strings have a uniformity to them, and a "point source" kind of quality, that makes it hard to imagine them as being a whole section of players.
You could a few slightly varying solo strings to a string section to get a bit more realism, but take care of the balance.
Another trick I've read about, but not actually tried, is to use portamento in legato lines (fast, short distances only). Some conductors seem to insist on it. But even when the strings play without it: when a string player moves his hand between notes, there will be a small pitch change at the onset of the 2nd note, which sounds somewhat like portamento. However, I think that can only work for individual players, not for the entire section, but it is something to tinker with.