To play a major third, play a note on any of the lower three strings. Then, play the note one string higher and one fret lower. For example, play the 12th fret on the third string (an A) with your second finger and the 11th fret on the second string (a C?) with your first finger. Alternately, you can play one note with your first finger, then shift up to play a note four frets higher on the same string with your fourth finger.

Try playing a major third several times, both in sequence and simultaneously. Listen to the sound and try to get it in your head. Or, think of the first two notes to "Kumbaya."

Major thirds can be useful to throw into bass lines. Every time you are playing under a major chord, remember that the note a major third above the chord's root is one of the chord tones. Use it in your bass line.