Two strings are placed in courses of two strings each and usually played together. The two strings in the bass are normally tuned an octave apart.
Each pair of strings in the treble is tuned in unison ( the same pitch) The tuning of the second string varies: some players use a unison tuning less prone to breakage, others prefer the a high-pitched, bell-like quality an octave tuning makes in this position.
As it is more difficult to pluck individual strings on the twelve-string guitar, and almost impossible to bend notes tin tune It is more suited to a rhythm, accompaniment, or solo role, and is often used in folk songs and some popular music. Sometimes hard rock and progressive rock musicians play double-necked guitars, having both six-string and twelve-string components, allowing the guitarist easy transition between different sounds.