Slide guitar is a particular technique for playing the guitar that is often used in blues-style music. The technique involves placing an object against the strings while playing to create glissando effects and deep vibratos that make the music emotionally expressive. It typically involves playing the guitar in the traditional position (flat against the body) with the use of a tubular "slide" fitted on one of the guitarist's fingers. The slide may be a metal or glass tube like 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 and is then referred to as "lap slide guitar" or "lap steel guitar".