The diddley bow is a single-stringed American instrument which influenced the development of the blues sound. It consists of a single string of baling wire tensioned between two nails on a board over a glass bottle, which is used both as a bridge and as a means to magnify the instrument’s sound.
The diddley bow is typically homemade, consisting usually of a wooden board and a single wire string stretched between two screws, and played by plucking while varying the pitch with a metal or glass slide held in the other hand. A glass bottle is usually used as the bridge, which helps amplify the sound. The diddley bow was traditionally considered an “entry-level” instrument, normally played by adolescent boys, who then graduate to a “normal” guitar if they show promise on the diddley bow. However currently, the diddley bow is also played by professional players as a solo as well as an accompaniment instrument.