Count the strings on a standard mandolin and you usually find eight. Count the basic open-string pitches and you find four. The strings are organised into pairs, commonly called courses, rather than eight independently tuned notes.
The Classical Mandolin Society of America’s notation guide gives the standard mandolin tuning as G3, D4, A4, and E5, with the strings in each pair normally tuned in unison. Other members of the mandolin family have different ranges, so identify the instrument before following a tuning chart.
Listen to one string, then its partner
A pair can sound slightly unsettled when its two strings do not agree. Before assuming the instrument needs a major adjustment, check each member of the course individually.
Peterson’s mandolin tuning guidance notes that plucking one string can cause its partner to sound as well, which can make a tuner’s display inconsistent. Gently damping the other string helps isolate the one you are checking.
For a beginner, a useful routine is to identify the course, sound one string, check the target pitch, then repeat for its partner. Make small adjustments with the correct tuning machine. If you are uncertain about the octave or the string fitted, stop and ask a teacher or technician rather than tightening until a display happens to show the right letter.
Four courses shape the playing experience
The paired layout also explains why a chord diagram may appear to describe four positions even though the instrument has eight strings. The fretting and picking need to engage the course cleanly.
Try a slow open-string exercise, moving from one course to the next and listening for evenness. A weak or rattling sound may come from contact, setup, or a string problem; it is not automatically a tuning issue.
Understanding the pairs makes the instrument less puzzling. You are learning four coordinated courses, while still paying attention to all eight physical strings.