- 4th course (thickest, nearest your chin): G
- 3rd course: D
- 2nd course: A
- 1st course (thinnest, nearest the floor): E
Those are the same four notes as a violin, tuned in fifths. To check your tuning, fret any course at the 7th fret: it should match the next higher open course. G at the 7th fret gives D, D gives A, and A gives E.
Because each course has two matching strings, a full set has two of each gauge. If one string in a pair breaks, it's usually best to replace both so they match.
For more, see how is a mandolin strung and tuned?, what gauge mandolin strings should I use? and our mandolin strings guide. Our sets are in Mandolin Strings.
