fretless

A fretless instrument is a stringed instrument whose fingerboard lacks frets—the raised bars on fretted instruments. On a fretless neck, pitch is determined by the exact point where the string is pressed against the fingerboard.

Because there are no frets to halt the string's length, players can slide smoothly between pitches and produce microtones, giving an expressive range not available on fretted instruments. This places greater emphasis on precise left-hand intonation, and vibrato and portamento are common expressive devices.

Common examples include instruments in the violin family (violin, viola, cello, double bass) and several traditional or regional instruments such as the erhu. In modern music, fretless electric bass guitars and sometimes fretless electric guitars are used in jazz, fusion, and experimental styles to exploit continuous pitch possibilities.

Intonation on fretless instruments can vary along the neck, and setup considerations such as action and neck relief affect performance. Fretless designs are chosen for their expressive pitch control and timbral qualities, despite the increased challenge of keeping notes correctly in tune.