Seven string guitar tunings is similar to the principle of a five-string bass guitar tuning. Seven-string tuning adds a low note for the extra string, being a fifth lower than the original sixth string - i.e. it is a low B note for standard 7-string guitar tuning.

Standard Tuning for 7-string guitar

B-E-A-D-G-B-E

1st string = E (highest)
2nd string = B
3rd string = G
4th string = D
5th string = A
6th string = E
7th string = B (lowest)

Example of 7-string guitar string set:
D'addario EXL110-7 Regular Light "10s"
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