What is claw hammer banjo?

Clawhammer or 'frailing' is an American banjo playing style that originated in the 19th century. It is one of the oldest and most popular banjo playing techniques. Clawhammer is characterized by its distinctive syncopated rhythm, in which the thumb, index, and middle finger are used to pluck the strings in a downward motion, while the pinky and ring fingers rest on the banjo head, adding a unique percussive sound to the music. This style of playing, which is often used in folk, bluegrass, and old-time music, typically provides the driving rhythm for the whole song.