Folk songs for Standard E (or drop tuned D) guitar?

[rectus_dominus]

Hi! I like playing and practising metal with my current low-tuned electric, but my granpa isn't really amused by it. So, mostly because of my grandfather's pleasure, I'd like to play songs which he would like listening to, when I get my new electric guitar.
I was thinking about learning some wonderful pieces of various folk music. Irish, Russian, Gypsy, Balkanic, anything nice. So far I barely found any usable guitar resource sites for this task, and those rare ones require different tunings which I'm not really familiar with.
If any of you Dear KvR have some online resources regarding this topic, please post it!
Thank you very much, cheers!