Watch the Using a Capo online guitar lesson by Andy Aledort from Slide Guitar Power
Another commonly used technique when playing slide guitar is to incorporate the use of a capo. In most cases, an open tuning is used in conjunction with the use of the capo, so that the home chord, the chord that is sounded when all of the open strings are sounded, is represented by the combination of the tuning and the capo position. But even in standard tuning, a capo is useful in that it changes the pitch of the open strings, which in turn broadens the scope of keys one can utilize without retuning the guitar. Keith Richards of the Rolling Stones is a good example of a guitarist that likes to combine capo use with the slide, as heard on songs such as "Happy" from Exile on Main Street.