1. Shortening the String Length:
To increase the pitch of a string, you need to reduce its vibrating length. This is achieved by pressing the string against a fret (for stringed instruments with frets) or stopping the string with your fingers (in the case of fretless instruments like the violin or double bass). By shortening the string, the portion that is allowed to vibrate is smaller.
2. Increasing String Tension:
When you press the string against the fret or stop it with your finger, you also increase the tension in the string. The tighter the string, the higher its pitch.
3. Faster String Vibrations:
As the string tension is increased, the string becomes stiffer and resists stretching more strongly. This causes the string to vibrate faster, producing a higher-frequency sound wave.
4. Tonal Change:
In addition to changing the pitch, altering the string's tension and vibration characteristics also affects its tone and timbre. The note may become brighter and more intense, or it may acquire a different harmonic quality, depending on the instrument and playing technique.
5. Finger Placement:
The exact position and pressure applied when stopping the string influence the note's intonation and clarity. Proper finger placement and technique are essential for producing notes with good pitch and tone quality.
By adjusting the string length and tension, you can control the pitch and produce different notes on a single string. This principle applies to all stringed instruments, whether they have frets or not.