The triple contrabass viol is a modern variant of the French octobass, closely related to the double bass.^{[citation needed]}

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Recordings and performances of sub-contrabass string instruments are rare; over 10 feet (3 m) tall, the triple contrabass viol must be played with the performer on an elevated platform. It was originally a three-stringed baroque instrument tuned C₀–G₀–C₁ or C₀–G₀–D₁ with the lower C coming in at 16.35 Hz. This is equivalent to the C two octaves below the cello's lowest C.

A four-string variant of the contrabass viol is played by bassist Brian Smith on Roscoe Mitchell's recording, Four Compositions (Lovely Music, 1988).^[1] It had two large circular holes in the body to facilitate recording.