slide guitar
A technique where a smooth, hard object is pressed against guitar strings and moved along the neck to produce gliding pitches.
In Depth
Slide guitar uses a tube of glass, metal, or ceramic worn on the finger to glide along the strings, creating a vocal, crying tone. The slide does not press the strings to the frets but floats above them, so intonation depends entirely on the player's ear. Slide guitar is central to Delta blues, Hawaiian music, and roots rock. Open tunings are preferred because the slide can then produce full chords at any position.
Delta blues legend Robert Johnson learned slide guitar at the crossroads, according to legend, but the technique actually originated in Hawaiian music and migrated to the American South.