The symphonic sound is now based on mandolins, fiddle, dobro, guitar, string bass, and banjo with some of Nashville's best voices chiming in with close vocal harmonies.

NPR: Moody Bluegrass: Rocking Through the Hills

The double bass is an unwieldy string instrument that stands more than six feet tall, and it can be physically demanding to play.

WSJ: Music Students Hit the Boxing Ring

The John Jorgenson Quintet features Stephan Dudash on five-string viola, Gonzalo Bergara on rhythm guitar, Charlie Chadwick on bass and percussionist Rick Reed.

NPR: John Jorgenson Quintet On Mountain Stage

In one corner is the Smoky Mountain String Band three guys in blue dungarees with a banjo, fiddle and upright bass.

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