I flat busted a gut over this!!
The violin’s owner is employed.
The actual difference is that the viola is a seventh larger in size and a fifth deeper in pitch. I play both, and my mutes are the comb-style and made of ebony. I’m not sure whether they’re still made. Some mutes are permanently attached to the instrument, and are simply slipped onto the bridge when in use.
Violas are baby cellos. They have the same strings as a cello, just at a higher octave. But they are superior to cellos, just like they are superior to violins.
Violas kick everybody’s asses in the orchestra.
And that’s all you really need to know about that.
QFT! I think that about covers it. 
Some cellos have sloping shoulders, but you don’t see them too often.
Flat? You mean you’re a trombonist? 
Violas don’t kick ass, they’re everyone’s whipping boy, and with reason: being a seventh bigger than a violin isn’t enough if you want to play a fifth lower. A viola’s soundbox is too small for what it’s trying to do, so it hasn’t the tone of either the violin or the cello. Unfortunately there’s no help for it owing to a world shortage of seven-foot violists who can pull up their socks without bending, which is what you would need to play a properly-sized viola. So the poor instrument has to be a compromise in order to fill the gap between cello and violin.
That said, Saint-Saens’s Le Cygne does lie within the viola’s range.
In training, I have got within a tone of the double bass’s lowest note.
This is not to provoke argument or disagree, but are you sure they were cellos? There are still a fair number of violas da gamba around, either vintage instruments or (rarely) new construction, for use in chamber music that calls for one of them. And they are visually identical to a “slope-shouldered cello” except for the rear soundboard, IIRC.
Or in other words, being an Oyarsa, you cheated!
::: mutters something about “music of the spheres”:::: 
Yep, you certainly need some “spheres” to sing as low as I can.
Keep dreaming, sugar tits. The viola is the middle child that no one loves. It doesn’t know what it is. The viola is confused. Sounds like a cello but without the rich depth of sound. Looks like a violin that ate one too many Mrs. Winner’s Super Cinnamon Swirls.
The only reason you sound good on the viola is because you are violin-trained! Don’t forget your roots, girlie.
Are you sure you’re not talking about cello players?
Someone needs to make a “cellino” - like a child’s cello but tuned an octave below the violin. Taking the range of the cello into account, ISTM that such an instrument could comfortably cover the notes the viola usually plays, and with a much better tone.
What’s more, if it were written for in the tenor clef (as would be logical), a cellist could play it without much mental adjustment - just play it as if it were a cello part written in bass clef! (With some minor modifications, but you see what I’m saying).
People have gone for radical ideas like this in the past - IIRC one included a full set of eight different-ranged violin-family instruments. The book which I read this in is with a pupil at the moment, though.
This is like saying that a viola part in the treble clef could be played by any violinist…it’s about more than just mental adjustment! (Obvious jokes ensue…)
I think you missed the point. On a cellino as proposed, the lowest note would be two ledger lines below the stave. The note the clef is on would be 2nd finger in 1st position on the second string down (the A string, on a cellino). Ring any bells?
I clearly am missing some point. It’s a violin-familiy instrument, with a tuning between that of cello and viola…is this a shoulder-held instrument (huge!), or a floor-supported one (problem because it’s not big enough)? Either way, who’s going to play it well, without relearning every part of their technique to fit the new structure?
(Maybe you’re hinting at using viols, but that’s a different matter entirely)
I thought it was the skid marks in front of the snake.
Tanya Huang, the violinist in a New Orleans band called Mother Tongue, is a master of the seven-string electric violin. The extra three strings extend her range down to a whole tone lower than a cello’s lowest note. In effect (albeit not exactly the same tone colors) she plays cello, viola, and violin all in one.
I was thinking of a floor-supported instrument because the viola is already as large as is practical for a shoulder-mounted fiddle, and it’s still not big enough for the job (as mentioned above). And having gone for that, I thought it might as well be lower-pitched than the viola so that it wouldn’t be impracticably small. Something about as big as a 3/4 size cello would be about the right size to be strung in G-D-A-E an octave below the violin and it would still have the range to get to the top of the treble stave (as the cello can get more than halfway up it, easily). And it would have a soundbox big enough to support a stronger tone than the viola’s. You’d need a rather longer spike than a cello, but not improbably so.
Then, as I say, being a fifth higher than the cello allows its notation to map more or less onto the cello’s given that it would have a C clef where the cello’s F clef is (second line down). Of course the fingerings and positions would be closer together but it would be no more of a shift from cello to cellino than from violin to viola - some retraining required, but broadly the same.
Interesting! Does the electric fiddle have any kind of acoustic resonator, or is it all down to the amp? I’d’ve thought the bass notes would really suffer from having short heavy strings, but what the heck, you have to try these things. 
Whatever acoustic shortcomings Tanya’s fiddle would have were it, you know, acoustic, are made up for by the electronics. She brought a full, thick, rich sound out of the cello-range strings but mostly played in the violin range anyway.
And again I say, interesting!
Of course, another approach that could be taken to the same end would be electronic transposition, like they use on karaoke machines. Have a foot switch for the octave-switcher and you’re back to having only four strings to manage. It’s swings and roundabouts though as I’m sure Tanya could pull off some amazing feats over the seven strings.
I’ve been idly fantasising about looking out a child’s cello in a secondhand shop and re-stringing it as above. Not sure what to use for an E string though - I don’t know if viola strings have enough extra length to fit a 3/4 sized cello. And the other problem is that I haven’t played cello in thirty years and was thoroughly mediocre then.
They make Vertical Violas which are big enough for the low notes but also big enough that you can play it like a Cello. As a result there’s a new instrument that fills the gap between the Violas, & Cellos, the Tenor Violin tuned G, D, A, E, an Octave below a Standard Violin.