Violin completely losing tension. A violin in which the tuning pegs are slipping needs to be repaired by a luthier or violin repairperson. Peg dope or peg compound, used regularly, can delay the onset of such wear, while allowing the pegs to turn smoothly. The tuning G–D–A–E is used for most violin music, both in Classical music, jazz and folk music. Other tunings are occasionally employed; the G string, for example, can be tuned up to A. The use of nonstandard tunings in classical music is known as "scordatura"; in some folk styles, it is called "cross tuning". One famous example
Guitar tunings tuned fifth string can provide a reference to tune the remaining strings by ear. Tuning forks which provide the pitch of the high E string (329.63 Hz) are also common. The guitar is conventionally an equal-tempered instrument. The frets are positioned logarithmically, creating equally-tempered pitches along each string. However, guitarists who tune by ear will typically tune “clean” so that dissonant beating between particular strings is minimized. In this way, open intervals can be more consonant. This is known as just intonation, which is at variance with equal temperament. When the guitar is tuned in this way, open tunings theoretically