FAO Howard Jones - I have been going into folk clubs for nearly 50 years There are people who play open tunings and people who dont't Classical and flamenco use altered tuning as well There are altered tunings in the blues for slide and the Vestapol tuning in the US

I would also dispute that the guitar is not widely found in British folk music I have seen lots in in every folk club I have been to.

I was asking about the specific advantages of DADGAD