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
Reentrant tuning and old-time music. The four string plectrum banjo (more often used in jazz) and the four string tenor banjo lack this shorter string, and are rarely tuned in re-entrant fashion. Reentrant tuning On a stringed instrument, a break in an otherwise ascending (or descending) order of string pitches is known as a re-entry. A re-entrant tuning, therefore, is a tuning where the strings (or more properly the courses) are not all ordered from the lowest pitch to the highest pitch (or vice versa). Most common re-entrant tunings have only one re-entry. In the case of the soprano ukulele, for example,