Musical tuning

Some instruments become 'out of tune' with temperature, humidity, damage, or simply time, and must be readjusted or repaired.

[1] Different methods of sound production require different methods of adjustment: The sounds of some instruments, notably unpitched percussion instrument such as cymbals, are of indeterminate pitch, and have irregular overtones not conforming to the harmonic series.

The resulting unison is more easily and quickly judged than the quality of the perfect fifth between the fundamentals of the two strings.

However, non-standard tunings (called scordatura) exist to change the sound of the instrument or create other playing options.

Violin scordatura was employed in the 17th and 18th centuries by Italian and German composers, namely, Biagio Marini, Antonio Vivaldi, Heinrich Ignaz Franz Biber (who in the Rosary Sonatas prescribes a great variety of scordaturas, including crossing the middle strings), Johann Pachelbel and Johann Sebastian Bach, whose Fifth Suite For Unaccompanied Cello calls for the lowering of the A string to G. In Mozart's Sinfonia Concertante in E-flat major (K. 364), all the strings of the solo viola are raised one half-step, ostensibly to give the instrument a brighter tone so the solo violin does not overshadow it.

Scordatura for the violin was also used in the 19th and 20th centuries in works by Niccolò Paganini, Robert Schumann, Camille Saint-Saëns, Gustav Mahler, and Béla Bartók.

4, the solo violin is tuned one whole step high to produce a harsh sound evoking Death as the Fiddler.

American folk violinists of the Appalachians and Ozarks often employ alternate tunings for dance songs and ballads.

Likewise banjo players in this tradition use many tunings to play melody in different keys.

Many Folk guitar players also used different tunings from standard, such as D-A-D-G-A-D, which is very popular for Irish music.

[5] The creation of a tuning system is complicated because musicians want to make music with more than just a few differing tones.

Similar issues arise with the fifth ⁠3/2⁠, and the minor third ⁠ 6 / 5 ⁠, or any other choice of harmonic-series based pure intervals.

Two differently tuned thirds: Just major third Play ⓘ .
And the slightly wider: Pythagorean major third Play ⓘ .
Man turning tuning pegs to tune guitar
Tuning of Sébastien Érard harp using Korg OT-120 Wide 8 Octave Orchestral Digital Tuner
The pitches of open strings on a violin. Play ⓘ
Cello open strings. Play ⓘ
Comparison of tunings: I IV V I . Play just ⓘ , Play Pythagorean ⓘ , Play meantone ⓘ (quarter-comma), Play well temperament ⓘ ( Werckmeister ), and Play equal temperament ⓘ
Prelude No. 1, C major, BWV 846, from the Well-Tempered Clavier by Johann Sebastian Bach . Played in just intonation.
Prelude No. 1, C major, BWV 846, from the Well-Tempered Clavier by Johann Sebastian Bach. Played in Pythagorean tuning.
Prelude No. 1, C major, BWV 846, from the Well-Tempered Clavier by Johann Sebastian Bach . Played in meantone temperament.
Prelude No. 1, C major, BWV 846, from the Well-Tempered Clavier by Johann Sebastian Bach. Played in well temperament.
Prelude No. 1, C major, BWV 846, from the Well-Tempered Clavier by Johann Sebastian Bach. Played in equal temperament.