I am toying around with some cello Vst having basically no experience with playing any string instrument and realized that the sound of my generated sounds is quite artificial which underlines the fact that I have no clue about how a cello is played.
Now while watching some tutorial about cellos I am wondering how many strings are typically played during a piece? The bridge is curved so you either won't or even can't play 3 or 4 strings at the same time, but do you play two of them? Or is this effect purely created by playing one string and letting it swing while playing the next string?
Bonus: Does a straight bow mean that only one string is played? :)
It is common to play double-stops, certainly in solo pieces; and indeed also quite common to play 3- or 4-voice chords (these need to be "broken", i.e. you quickly excite the low strings and let them ring, then pull the bow up and sustain the high strings).
Indeed the multi-stringedness might have something to do with what you call "synthetic" sound you're suffering from: most of the time, even if only one string is actively played, the other are free to vibrate and cause sympathetic resonance. But this influences the sound only subtly anyway, so it probably isn't your main problem.
"straight bow" is more to the point. This is orthogonal to how many strings you're playing... literally: a straight bow is when the angle between the bow and string is 90°. This is normally the best angle to get a good solid sound1.
Angle is just one of many bow parameters:
- Default position for the bow on the string is between the bridge and the beginning of the fingerboard, a bit closer to the fingerboard but by no means above it2.
- The bow itself can be angled axially, i.e. you can either have all bow hairs flat on the string or you use mainly the upmost hairs. Again, straight is a good thing to practise first, though it's generally ok to have an angle here (it gives a bit of a sweeter sound).
- Pressure is of great relevance. You'll often hear the advice "use your arm's weight", i.e. you should be relaxed yet excert a firm and steady pressure on the bow against the string.
- Same goes for speed. You can move the bow fast or slow, but you need to be deliberate about it, and consistent.
Controlling all these parameters in realtime is, obviously, not easy. Apart from the inevitable practising effort, you should make sure you're holding the bow the correct way. You'll find many pictures on the internet, but really – asking a teacher to show it to you is much more effective. There are many bad habits you can develop in the right hand.
So that was only the bowing aspect. Of course, when playing proper cello pieces you also need to be very accurate about the left hand fingering. But before you blame it on the left hand ("more vibrato" is definitely not the solution to your problem, though it might initially seem to help), make sure you get the bowing right.
Now, the above block hints at what's the real problem with VST strings: there's a darn lot of parameters a good string player controls simultaneously, to get the right sound at every moment in a performance. If a note is repeated, even if it's nominally the same length and dynamic level, it'll sound different because the bow is moving the other direction. If a passage is played quickly / staccato, the player will put in more pressure on the beginning of the tones so the notes develop fast enough, whereas in slow / legato it's more of a soft fade-in. For some intervals you might need to perform a particular position change that gives a barely noticable, but characteristic sound (in particular on the cello, position changes can make quite an audible portamento even when the player hides it).
Today's top-notch plugins, e.g. the Embertone Blakus Cello, will generally offer ways to emulate all such effects. But it'll only sound natural if you actually know how to correctly place the effects.
There's one particular thing I consider paramountly important but is largely neglected by vendors of such plugins: intonation. Though players of guitar or piano will regularly claim otherwise, string instruments do not play in 12-edo tuning. Every single note is actually fine-tuned to some pitch that can depend on lots of factors; it's normally said that string players switch between Pythagorean tuning and just (5-limit) intonation, depending on the context.
1Good players will often deliberately angle the bow in various ways, but (unless you want to provoke e.g. a particular screech sound) this must be combined with controlled moving of the bow point. Before you try any of this, make sure you know how to bow straight.
2You'll sometimes find an indication "sul tasto", this means you should bow right at the edge of the fingerboard. Again, this is something to use as an effect.
Yes it is quite common. The technical term for this is double stop. Note, that independent of form of the bow the hairs are just fixed at the tip and the frog. So the hairs have really no choice but to form a straight line (but are deformed by contact with the strings). Even since the string arrangement is curved, it is easy to find an angle, where the bow has contact to two strings, with more force even three.
String instruments are quite hard to synthesize due to the complicated waveforms and even more complicated attack behavior, i. e. the sound phase at the beginning of the tone. This frequently sounds more artificial than the sustained tone later, so it is likely, that it is not your fault.
A cello has four strings, tuned in fifths: C, G, D, A (just below middle C).
It is possible to simultaneously play any two strings that are next to each other. The bowing is generally not difficult.
To be realistic, though, you also have to consider the fingering. Some limitations to consider are:
Those limitations are simplified when one of the notes is played using an open string.
It is also possible to play three strings simultaneously, since there is some elasticity in the bow . However, such triple stops are limited in duration, since a long stroke will prevent the middle string from vibrating freely, and the tone quality will be poor. Triple stops would commonly be used for, say, the final chords of a symphony. They would all be down-bow strokes.
The caveats of double-stops also apply, of course.
Four-note chords can be played as well, by quickly rolling the bow. For example, C-G-E-C can be played by a C+G double stop (easy, since they are both open strings), followed immediately by an E+C double stop on the D and A strings.
A good illustration of double stops and rolled chords is the Sarabande from Bach's Cello Suite No. 1. The score (I use "the" loosely, as there are many editions, some of which differ significantly) calls for double, triple, and even quadruple stops. However, since it is very much a legato piece, these ideal chords can only be approximated by rolling. In actual execution, no more than two strings are being played at any given instant.
I don't play cello, but I'll answer this based on what I do on double bass.
Simple answer: You can play two strings together. It is common to play several strings together.
how many strings are typically played during a piece?
All of them. I think you wanted to ask
how many strings are typically played simultaneously during a piece?
Αnd the answer to this depends on the song.
There is no rule that tells you you have to play only one or two strings at a time. If a cello plays with a piano, you might not need to play chords. If a cello plays alone, it might need to play some chords; thus playing two strings together.
From my experience, the most 'typical' songs have mostly single strings being played, but it is not uncommon to see chords on a cello. I have seen it many, many times.
My personal answer to this would be: Play as many strings simultaneously as you want.
Does a straight bow mean that only one string is played?
No. With a straight bow (I've never seen a curved one -- normal bows are straight) you can play up to 2 strings together, since the instrument is curved.
There are many great answers above, here's a bit more. I play the cello, and as mentioned above, you can play 2 strings at a time. This is known as a double stop. It is quite common and I think it sounds great.
If you're utilizing sampled cello sounds, you'll definitely meet a challenge in trying to make it sound convincing or realistic. However if you require more than 2 notes at a time with the string sound, you can write the remaining notes for the viola or violin, or you can write the piece for multiple cellists.