I had to look up tenor viol. At least I now know where does your nickname come from.
The viol aka viola da gamba shares a common ancestor with the guitar, which explains the six strings and the frets. The ancestor is the vihuela, which was a plucked instrument aka vihuela de mano i.e. played with the hand. The name tells you it was Spanish, possibly of Arabian origin.
Somewhere around 1400ish, some people try to play the vihuela with a bow. Eventually, it was turned upright and supported on the leg... which is where the Italian name 'viola da gamba' comes from 'on the leg'.
The vihuela de mano becomes the guitar.
Note that viols are not related to violins - they are two distinct groups of instruments. The main viols are treble, tenor, bass, and the 'violone' - double bass.
The desire to play louder in bigger venues was a problem for viols. The two basic ways pre-electricity to make things louder was to increase string tension and use metal strings. The neck construction of the viol limited how far you could take that. Violins could take more tension and they took over. By the start of the C18th, only the bass is really in regular use as a bass continuo instrument in baroque music. After 1770 or so, viols have dropped out of use except in niche areas. It remains like that until the C20th and the revival of interest in early music.
With one exception... the violone. If you have ever locked at double basses, you may have noticed that there are two different styles/shapes. Some have square shoulders - these are 'bass violins'. Some have sloping shoulders - these are in fact violones, minus 2 strings and their frets.
(bottom of page)
