Sound is produced by moving the bow over the string or by plucking it with the right hand. Pitch alterations are achieved by pressing down the string with the fingertips of the left hand on the fingerboard. This shortens the vibrating portion of the string and raises the pitch.
The cello is held upright between the legs with the tail-pin resting on the ground. This position is so stable that no additional support is necessary from the left hand, all the fingers of which including the thumb are free for fingering.
The thumb position has been in widespread use since 1740, chiefly for the high positions of the A and D strings as well as for double stops (in octaves) and artificial harmonics.
Change of string and change of position
The cello has four strings tuned to intervals of a fifth: C2 (4th string), G2 (3rd string), D3 (2nd string), A3 (1st string). The strings are an octave lower than the viola’s. The bottom string is closest to the bowing hand.
In principle there is no difference between sound production on the cello and on the smaller bowed instruments. But because the strings are twice as long as the violin’s the distance between whole and half notes on the fingerboard is greater. The result is a special fingering system.
The fingering is chromatic: each finger plays a semitone, except the 1st and 2nd fingers, which can play whole notes even in the lowest positions. This means that the 2nd, 3rd and 4th fingers each cover a chromatic degree, while the 1st and 2nd fingers can reach over a whole note. The widest interval that can be fingered on one string without changing positions is therefore a major third, occasionally even a fourth.
The fingering described above is valid up to the 6th position. The greatest differences in playing techniques compared to the smaller instruments are therefore between the 1st and 6th positions.
The thumb position is used from 7th position.
Up to 6th position the thumb can slide freely up and down the back of the neck. But from the 7th position the body prevents the thumb rising any higher, so it is used for fingering. From the 7th position diatonic fingering is used, as on the violin, since the distances are smaller.
From 8th to 14th position, only the A string is used. Without the use of the thumb position octave fingerings cannot be played by cellists with smaller hands.
Natural harmonics are played by touching the open string lightly with the finger at the desired point. These respond very well on the cello and are used up to the 8th partial. On the string they can be played up to the 16th partial.
Artificial harmonics are usually produced by touching the string at a fourth.
To improve the timbre high positions on the bottom strings are avoided. Articulation is nowadays achieved by energetic fingering (percussion).
The bow is held at the frog by all four fingers of the right hand. The thumb and middle finger are opposite each other. The pressure of the bow is regulated mainly by the forefinger. The wrist is the most active joint, the elbow and shoulder remain as still as possible.
The entire length of the bow must be held at right angles to the string. This produces the purest notes.
The bow is thicker at the frog than at the point. Short, rapid notes are generally played at the point. The speed of bowing must be altered to correspond to the pressure of the bow; a faster speed of bowing with higher bow pressure produces a louder sound.
All string players distinguish between two basic forms of bowstroke:
The upstroke, the stroke from the point to the frog. As a rule it is found on unaccented beats and has a crescendo tendency.
The downstroke, the stroke from the frog to the point. It is found on accented beats (the beginning of a measure, accent) and has a decrescendo tendency.