Watch the E major in 3rds online guitar lesson by Brad Carlton from Guitar Lab: Chord Scales Vol. 1
Now we'll go back to the 4th and 3rd strings and study intervals of 3rds. 3rds are simply every other letter of the major scale. There are 2 intervals that we will use: major 3rds, which are two whole steps apart, and minor 3rds which are one and a half steps apart.