Other extreme bass instruments:
- octobasse: https://youtu.be/12X-i9YHzmE
- subcontrabass saxophone: https://youtu.be/kgt2m9Q7Kz0
- subcontrabass flute: https://youtu.be/dA70S6NJsCw
- subcontrabass recorder: https://youtu.be/U3CsmeKU2vE
- subcontrabass tuba: https://youtu.be/OK1GDkvFdL4