Mandolin tuner

Standard mandolin tuning, from the 4th course to the 1st: G D A E. Frequencies are for A4 = 440 Hz.

A mandolin has eight strings in four pairs called courses. The two strings of a course are tuned to the same note, in unison rather than in octaves, and are played together as one. From the lowest course to the highest the notes are G, D, A and E, the same as a violin's open strings, which is why mandolin players can read violin music directly.

Tuning the two strings of a pair to each other matters as much as tuning them to the note. If one string of a course is even a few cents away from its partner, the pair beats: you hear a slow wobble or a chorus-like shimmer instead of one clean note.

The tuner shows one button per course, since both strings of a pair share a note, but it hears one string at a time best. Each of the eight tuning keys turns one string, not a pair, so follow the string from the nut to its post before you turn.

Finish each course by ear. Pick both strings together: when they are in unison the wobble stops and the note sounds like one string, only fuller. If the wobble speeds up while you turn, you are moving away from the partner, so turn the other way.

The E strings are thin steel under high tension and snap easily if you overshoot. Bring them up slowly and stop at the green zone.

Because the courses are a fifth apart, the frets give you a quick cross-check: the G course at the 7th fret is the same note as the open D course, the D at the 7th fret matches the open A, and the A at the 7th fret matches the open E. Any pair that beats points to the course that needs another look.

On most mandolins the bridge is not glued; string pressure alone holds it in place. It is positioned so that notes up the neck play in tune, and it can shift when strings are changed or retuned by a lot. If the open strings are in tune but fretted notes higher up are consistently off, check the bridge position before blaming the tuning.

Eight strings pull on the neck and the top at once, so bringing one course up to pitch can pull the others slightly flat. After the first pass, go over all four courses again; the second round is quick.

In a jam with fiddlers, your A course and their A string are the same A4. Either everyone tunes to the same reference, or you tune your A course to the fiddle's A and the other courses from it, so the whole group agrees even if it is not exactly at 440.

Larger mandolins keep the tuning in fifths. The mandola is tuned C G D A like a viola, the octave mandolin G D A E one octave below the mandolin, and the mandocello C G D A like a cello. Use the viola tuner for a mandola, the cello tuner for a mandocello, and the banjo tuner's Irish tenor setting, G2 D3 A3 E4, for an octave mandolin.