It is difficult to speak about Bow Speed in an isolated form. Before reading this page we need to read the preliminary page “Bow Pressure, Speed, Point of Contact and Hair Angle” which discusses the intimate interrelationship between these four bowing factors. It is also useful to read the specific pages dedicated to each one of these elements, especially the page dedicated to Bow Pressure, with which it shares certain material.
According to the painting analogy that we used in the Bow Pressure, Speed etc page, bow-speed corresponds to the same two elements (darkness and paint quantity) as bow pressure, but in exactly the opposite way. Whereas greater bow pressure leaves more paint on the canvas (or ice-cream in the spoon), a greater bow speed (normally associated with less bow pressure) leaves less paint on the canvas and thus creates a “lighter” and “whiter” sound. A high speed+low pressure bow stroke corresponds to delicate water-colours or pencil drawings whereas a high pressure+low speed bow gives exactly the opposite effect, comparable to thick oil painting. It’s not surprising that the “ultimate” fast-bow (flautando sul tasto) is used so often in French impressionist music, as this type of bowing gives a sound that corresponds perfectly to the lightness and delicacy of the French impressionist painting style.
THE PRESSURE/SPEED RATIO: THE SCRATCH AND THE CONCRETE-MIXER
We can see that bow speed and bow pressure are normally like opposites: yin and yang, male and female, black and white, but that they are intimately linked to each other. We could usefully use the concept of the P/S ratio, where “P” = bow pressure and “S” = bow speed. As this value gets higher, our sound gets thicker and denser (oil paints), whereas as it gets lower, our sound gets “airier” (watercolours). When this value becomes unbalanced, we enter into the world of special effects. Whereas “sul tasto flautando” (created by a very low pressure and high bowspeed) is a valid musical effect, the same cannot be said for what happens to the sound when the pressure side of the equation goes through the roof. This causes some very unmusical sound-effects. When it happens at the start of the note, we get a scratch. And if we continue with this excess pressure (in relation to speed), then we get the concrete-mixer sound (rough and grinding). Thus the scratch and the concrete-mixer sound are the highly audible symptoms of a bow pressure that is too high in relation to the bow speed. Or, to say the same thing from the opposite perspective, the scratch and the grind are symptoms of a bow-speed that is too slow relative to the bow-pressure. To fix this, either we speed up the bow, or relax the pressure ……. or both! As a general rule we could say that an excess of bow-pressure is not only more dangerous but also much more common than an excess of bow-speed. This is why many excellent cellists are very cautious with their use of the word “pressure”, preferring usually to talk more about bowspeed as the source of phrasing and dynamics.
PHRASING AND DYNAMICS: PRESSURE OR SPEED?
Dynamics and phrasing are almost entirely a question of this bowspeed/pressure relationship but energy, vitality and “air” always come from bowspeed. And in fact, dynamics very often refer more to an energy level rather than a decibel level, which emphasises the importance even more of bowspeed in relation to pressure for making phrasing and dynamics. When high bowspeed and pressure combine together, we get the potent fireworks an extremely high energy ff, whereas we can make the difference between a high-energy (french) pp and a tragic deathly pp simply by varying our bowspeed with an identical pp bowpressure: high-energy =fast bow, while tragedy = low energy = slow bow (see below).
BOWSPEED IN SOFT PLAYING: HOW SLOW IS TOO SLOW?
Bowspeed gives vitality, energy, projection, resonance and quality. Even when playing very softly, we still usually need all these ingredients, even in discreet “pp” accompaniments. Think about unamplified theatre and singing. Actors and singers often need to do their stuff (talk/sing) softly, but at the same time they always need both projection and intensity. A performers sound not only has to be heard everywhere in the room, but also must have “resonance” – unless we deliberately want the passage to sound choked, suffocating, dead or dying. It is bowspeed (rather than pressure) which gives us this resonance.
If an actor or singer runs out of breath, their voice not only sounds soft, but also weak. They would probably describe this problem as “having no support”. Their support comes from the air that they have in their lungs(?) but in our case, our “support” comes, not from anything to do with pressure, but rather from the speed of the bow. Below a certain bowspeed the string cannot vibrate freely and the sound becomes strangled, as if we were choking or suffocating, exactly like a singer running out of air. For a singer, the solution is to take another breath, but for us, the solution to a choked sound is to use more bow (= faster bow). It is almost always better to discreetly break a slur than to choke for lack of oxygen (bowspeed). We can find thousands of examples of this in the repertoire because composer’s long slurs are almost always just phrasing indications rather than bowing indications – see Choosing Bowings. Also, instead of long whole bows, when playing “pp” it may be better to use more bows in order to stay in the upper half of the bow, where it is so much easier to play softly.
There is however one special effect that very slow bows do provide, apart from the dead sound. A very slow pp bow has a dramatic visual, choreographic effect: suddenly, the movement stops, we are hanging by a thread, holding our breath, our air is running out, we are pleading, whispering, exhausted, afraid, pulled back, hiding, about to burst into tears etc ….. it is hard to make these special effects if we are merrily sawing back and forth with our bow!
2: BOW DIVISION
Normally we plan our bowings to avoid sudden and extreme changes in bow speed, pressure and point of contact (unless deliberately desired for special effects). This planning is called the science of Bow Division and represents the culmination of all our knowledge, mastery and experience of bow use. Bow Division is a little like singers’ planning of their use of the breath, only infinitely more complex because not only do we change our bow so much more often than a singer breathes but also because we play on both inward and outward breaths (down and up bows). This planning is especially complex and difficult in figures in which the alternation of long and short notes note creates “asymmetrical” patterns (see Dotted Rhythms and Choosing Bowings).
3: AVOIDING BOW SPEED BUMPS IN DOTTED RHYTHMS
Assymetrical bow patterns – especially repeated dotted rhythm figures – pose special problems for Bow Speed and Bow Division. Try the following patterns:
These repeated dotted rhythm figures create the danger of “speed bumps” or “bunnyhops” (accents on the short notes) produced by the fact that we have to use a much faster bow on the short note in order to avoid our bow gradually working its way more and more to one end.
There are several ways we can avoid this:
3:1 RADICALLY ALTERNATING SPEED/PRESSURE CHANGES
The word “radical” is well-chosen here as the changes in the bowspeed-bowpressure relation that we need to do (in order to avoid either making accents on the short notes or ending up in the wrong part of the bow) are both huge and sudden. On the longer notes we need a heavy bow pressure and slow bow speed, whereas on the short notes we need just the opposite: fast speed and low pressure. This rapid alternation of opposites is quite tricky to achieve and is almost like a magic trick. Making a success of this trick is greatly helped if we release the bow pressure at the end of the long note.
3:2 “RETAKING” THE BOW
If we can lift our bow off the string before or after the short note, then this enables us to move our bow, silently in the air, back to where we want it to be. This, along with “hooked bowings” (see below) is one of the easiest way to solve the problems of bow division posed by repeated dotted figures. We have two choices for when to retake the bow:
1: In a brief “gap” after the long note, which is often not written as a “gap”:
It is surprising just how often we can make this “gap” after the long note, even when it is not specifically written as a rest. If, near the end of the long note, we remove the bow from the string in the appropriate way (see Note Ends), that long note will keep sounding even without any bow contact, and this resonance – like the piano’s sustain pedal – creates the aural illusion that we are still sounding it with the bow. Basically, what we are doing then is putting in a little comma, during which we bring the bow back towards the frog. Below, the retakes are indicated with this comma instead of with the arrow. In all of the edited sheet music available on this website, the comma indicates this type of retake.
In most of the above examples we were retaking to an upbow. We can of course also go “the whole way”, and retake to another downbow, as in the Brahms Sonata example.
2: In a brief gap after the short note
3:3 HOOKED BOWINGS
Very often we will encounter asymmetrical passages in which the musical articulation does not allow us to lift our bow off the string. Here we will most probably use “hooked” bowings in which we “hook in” the little note in the same bow direction as the previous longer note to avoid “speed bumps”.
The back legs of rabbits are much more powerful than their front legs. This is why their running rhythm resembles more a dotted rhythm than the regular binary flow of other animals whose front and back legs are more symmetrical. Playing asymmetrical rhythms with hooked bowings avoids our sudden fast bow stroke giving this same “bunnyhop accent” to the short notes.
Retakes and hooked bowings are a wonderful solution for avoiding bunnyhop accents. Unfortunately however, their use is not always possible. For a more detailed discussion of these situations, and about finding the right bowing for asymmetrical musical figures in general, see the “Choosing Bowings” section.
BOW SPEED VARIATION IN SHIFTS
Very often, to hide an unwanted glissando in a slurred position change we can simply slow down the bow speed (and/or reduce the pressure) during the shift, making a sort of portato effect. If we do this discreetly, then the interruption to the legato line can be imperceptible, whereas the musical advantage of avoiding an unwanted smear/smudge can be considerable. This is especially useful in music of the Classical Period in which glissandi were not yet the important expressive device that they became in the Romantic Era.
This technique is also useful to help with obtaining a clean start to any note that is slurred to an immediately preceding harmonic on the same string. If we maintain constant bow speed and pressure after the harmonic, then the new finger has a high risk of starting with a squeak rather than with a clean start. The exceptional resonance of the simple natural harmonics means that the interruption to the legato line due to this momentary bow relaxation is usually imperceptible.
BASIC EXERCISES FOR VARYING BOW SPEED
Just as for “Point of Contact” and “Bow Pressure”, we can observe the interrelationship between Bow Speed and the other bow variables by experimenting along the following lines:
1. Vary the bow speed without changing any of the other variables (pressure, point of contact, bowhair angle, left hand position)
2. Vary the bow speed while simultaneously varying one other variable, for example:
………. left hand distance from bridge
……….. bow pressure
……….. point of contact
3. Vary the bow speed while simultaneously varying two other variables, for example:
………. left hand distance from bridge AND bow pressure
……… left hand distance from bridge AND point of contact
………. bow pressure AND point of contact