Where can one find guitar chords for Irish traditional music on the Internet? Thanks!
In standard tuning, get a “chord dial” and use only the straight major and minor chords for the key of the tune. I have NEVER played a diminished chord in ITM.
If you would rather play in DADGAD tuning, do a Google search on DADGAD and see what you find.
Hopefully this helps.

http://www.sassafrassgrove.com/ChordBook/NEMOFOTMADChordBook.html
I’ve not published it online yet, but it is available in book form.
That could be VERY handy! I seem to remember something called the “Squaredance Chord Book” (or something like that), that used a similar approach.
I personally don’t like playing backup guitar, but often find myself in that situation anyway. The book could save me some time trying to puzzle things out. Also, it could be a GREAT teaching aid for newbie rhythm guitarists who want to join in quickly. Cool!