Ab / Fmin and improvise from there ?  LOL - sounds like a fun piece to improvise to...

EDIT: there are other ways for getting to grips with something like this - download the video, extract the audio as a .mp3 file, and use some of the (free) tools for slowing-down audio (the pitch doesn't change).    You can do this with Audacity, or programs like "Timestretch" amongst many others - google "mp3 slowdown"

The violin doesn't sound overly complex (other than some of it being played in a higher position I suspect) - and is something you would be able to "get-in-your-head" without recourse to sheet ?      Just a thought....