Open B tuning

Open B Tuning is an open tuning for guitar. The open string notes in this tuning are B-F-B-F-B-D. It uses the three notes that form the triad of a B major chord: B, the root note; F, the perfect fifth; and D the major third.
When the guitar is strummed without fretting any of the strings a B major chord is sounded. This means that any major chord can be easily created using one finger, fretting all the strings at once.