Fingerstyle. "Thumb and one" and Mumford and Sons' White Blank Page

"Thumb and one" is a term we use to describe a fingerpicking style that mainly uses the thumb to pick the bass notes and one finger, usually the index (i) to pick or brush the treble strings.   The Beatles' 'Yesterday' and 'Blackbird' were played with this technique.  Also the song 'White Blank Page' by Mumford and sons, shown here.  Thumb and one is often associated with traditional or roots music styles.  Frequently the players describe their techniques as not very advanced, although the players are often playing very well.