The double bass is the largest and lowest-pitched member of the orchestral string family. Standing over 6 feet tall, it can be played with a bow (arco) or by plucking (pizzicato). In classical music, it provides the deep harmonic foundation, often doubling the cello parts an octave lower. However, in Jazz and Rockabilly, the double bass became a rhythmic powerhouse. Jazz bassists like Charles Mingus and Ron Carter popularized the 'walking bass' line, while Rockabilly players introduced the 'slap bass' technique, where the player pulls the strings so hard they snap back against the fingerboard, creating a percussive 'clack.' Unlike the rest of the violin family, which is tuned in fifths, the double bass is tuned in fourths (E, A, D, G). This tuning was adopted to make the long reaches between notes more manageable for the player's left hand.