Frets & Knots

One of the most critical factors for both playability and accurate intonation on a stringed instrument is the fingerboard. Stringed instruments are generally divided into two main categories, depending on the tonal system they follow.

The first category consists of unfretted instruments. On these instruments, the performer has full control over the pitch of each note through finger placement along the fingerboard. Examples include the oud, violin, fretless guitar or bass, cello, and double bass.

The second category consists of fretted instruments. These instruments feature fixed frets on the fingerboard that define the pitch intervals according to the instrument’s construction or setup. Fretted instruments facilitate playability and are predominant in the musical community. However, because they rely on tempered tuning, some intervals deviate slightly from natural harmonic ratios.

In Western music, the equal-tempered system has been standard since the 19th century, originally developed for piano tuning. In this system, the octave is divided into twelve equal semitones, which introduces minor compromises in certain intervals. This allows instruments to play in any key, though some intervals may deviate by several Hertz from their pure harmonic position. Modern fretted instruments such as guitars, basses, bouzoukis, and most other fretted stringed instruments follow this system. The frets are permanently installed and cannot be repositioned.

Over time, frets wear down, which can manifest as string buzz, compromised intonation, or difficulty performing techniques such as bends. Similar issues can arise from impacts to the fingerboard, lifted or loose frets, or low-quality fingerboards, common in entry-level instruments.

A professional guitar tech or luthier will recommend solutions tailored to the instrument’s condition. The two most common corrective procedures are:

• Fret dressing (leveling, crowning, and rounding fret edges)

• Refretting (replacement of worn or damaged frets)