So I learned to tune the fiddle - start with the A string, tune the the D string down then up, then tune the G string down then up to match the D string. The E string gets tuned down. I had never tried tuning like this, I guess I had it easy with the guitar, you are playing the same note. However I was able to hear the beats of the 5th interval while tuning the fiddle.
My teacher asked me if I minded learning something that wasn't Irish, I was like fine by me, so she assigned me Cattle In The Cane. It's a bit weird learning something that isn't a jig or reel, it takes me a bit longer to "get" the tune but that's not a big deal.