An hour and a half on one choon?!

No, seriously, very nice, but the intro is arhythmical and horrible and would put me off if I were playing the violin to it.

Also it's a good lesson in using hooked bowing in triple time.

There are two Wohlfahrt studies you should look at.

Op.45 n.20 and Op.74 n.34

Different notes, same rhythm, same idea, clearly.

Op 74 is intended to be easier than Op 45 - it's a later rewrite, I guess.

Notes and rhythm should be very familiar to everyone. I have no idea if Wohlfahrt inspired or was inspired by the Valse Musette. I assume the latter.

I like this first teacher normally, but he loses the rhythm badly at times: -

https://www.youtube.com/watch?.....Dxakh7vIGM

The second teacher also loses it, although he attempts to cheat: -

The key is to stress the first and third beat of every bar. Cutting the long notes short inreases the danger of it sounding like 6/8 instead of 3/4, and playing it fast is obviously trickier than playing it slowly.

It looks like I can only post one youtube link per posting.

chromaticism...I don't know enough about music theory to know how it treats that 

I've blundered here. It's important to realise that "music theory" (i.e. Western classical music theory) is a very limited animal. It only analyses the 12-tone harmonies our ET keyboards generate. Other instruments, such as African ouds, Spanish guitars and French accordions, generate voice-led(?) harmonies that simply aren't dealt with by "music theory".

Ugh, some kind of forum bug - an intervening post accidentally got deleted.

I had said that the accidentals are because #20 involves modulating between the keys of Bb, Gm and D7 with chromaticism as well, which is part of the bal-musette sound (as we agreed, possibly from the keyboard of a squeezebox).