What is Slide guitar?

Slide guitar is a technique for playing the guitar that is often used in blues music. It involves playing a guitar while holding a hard object against the strings, creating the opportunity for glissando effects and deep vibratos that reflect characteristics of the human singing voice. It typically involves playing the guitar in the traditional position with the use of a slide fitted on one of the guitarist's fingers. The slide may be a metal or glass tube, such as the neck of a bottle. The term bottleneck was historically used to describe this type of playing. The strings are typically plucked while the slide is moved over the strings to change the pitch. The guitar may also be placed on the player's lap and played with a hand-held bar.