Bottleneck guitar

Slide guitar is a particular method or technique for playing the guitar. Instead of altering the pitch of the strings in the normal manner (by pressing the string against the fingerboard close behind the frets), an object called a "slide" is placed upon the string to vary its vibrating length, and pitch. This slide can then be moved along the string without lifting (hence the name), creating smooth transitions in pitch and allowing wide, expressive vibrato.

Slide guitar is most often played (assuming a right-handed player and guitar):

The technique of using a slide on a string has been traced to one-stringed African instruments similar to a "Diddley bow".

The technique was made popular by African American blues artists. The first musician recorded using the style was Sylvester Weaver, who recorded two solo pieces "Guitar Blues" and "Guitar Rag" in 1923. Some of the blues artists who most prominently used the slide include gospel singer Blind Willie Johnson, Blind Willie McTell, Mississippi Fred McDowell, Charley Patton, Son House, Robert Johnson and Casey Bill Weldon.

The first influential classic electric blues slide guitarist is arguably Elmore James, who in 1951 created a slide guitar interpretation of Robert Johnson's 1936 "Dust My Broom" riff, and is held in particularly high regard. His slide and bottleneck guitar techniques were later widely adopted by blues and rock guitarists—including British blues bands such as The Rolling Stones, The Animals, and The Yardbirds, and rock guitarists such as Eric Clapton, Jimmy Page, Jeff Beck and Jimi Hendrix. Blues legend Muddy Waters was also very influential, particularly in developing the electric Chicago blues slide guitar from the acoustic Mississippi Delta slide guitar. Texas blues musician Johnny Winter developed his distinctive style through years of touring with Waters. Slide player Roy Rogers honed his slide skills by touring with blues artist John Lee Hooker. John Lee's cousin Earl Hooker may have been the first to use wah-wah and slide together.

...
Wikipedia