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 double-bass is played in the standing position with the tail-pin resting on the floor.
The thumb position is used mainly in high positions and for double stops and artificial harmonics.
Change of string and change of position
Five strings with an interval of a fourth are available: B0 (5th string), E1 (4th string), A1 (3rd string), D2 (2nd string), G2 (1st string). The bottom string is nearest the bowing hand.
There is no fundamental difference between sound production on the double-bass and on the smaller bowed instruments. But because the strings are more than three times as long as the violin’s the distance between whole and half notes on the fingerboard is greater; for example, on the double-bass the length of a violin fingerboard is necessary to play a major third (two whole notes). The result is a special fingering system.
As on all stringed instruments, fingering is based on the system of positions. Because of the great length of the strings (95–115 cm) the distances between the half steps are very wide. It is for this reason that the strings are tuned to fourths and not fifths.
The fingering is not consistently chromatic; without changing position a whole tone step is the most that can be fingered: for example, if the forefinger plays an E on the D string the middle (or ring) finger can reach F and the little finger F#. G is the next open string.
Up to the thumb position (from 7th position) the ring and little fingers are treated as one single finger. The playing fingers are therefore the forefinger, middle finger and little finger (the ring finger is often used to support the little finger, in accordance with the anatomy of the hand).
The fingering described above is valid up to 6th position.
The thumb position is used from 7th position. There are five thumb positions. Every position is used on all four strings. From the 3rd thumb position upward only the two top strings are used.
Natural harmonics are played by touching the open string lightly with the finger at the desired point. These respond very well on the double-bass and are used up to the 6th partial on the H and E strings, and up to the 8th partial on the A, D and G strings. Even higher harmonics than these can be produced and are also called for in solo pieces. The notation of harmonics is non-transposing (an octave higher than the notes played by pressing down the string), the sound is as written due to the pitch in treble clef.
In contrast to the higher bowed instruments only a very limited number of artificial harmonics can be played on the double-bass. In the lower register touching the strings at a third, fourth or fifth produces no harmonic. Artificial harmonics at a fourth are possible between the 1st and 8th thumb positions and are usually only played on the G string.
Bowing is essentially the same as on the higher-pitched bowed instruments.
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.