Several essays and other instructional material, including a lot about DAA chords, on news page at http://www.english-dulcimer.com/news.asp
blurb on home page: " Dan plays mountain dulcimer almost exclusively finger-style. His instruments have three single strings and have been built with a diatonic fretting pattern, there are no half-frets.
On the dulcimer Dan’s repertoire includes traditional English, Scottish and Irish folk songs and airs as well as a few fun original compositions and the occasional timeless classic. He takes a classical approach to British folk melodies with medieval modes and jazzy chords and rhythms."
Ionian / DAA Ionian mode, commonly referred to as DAA, is Dan’s favourite mountain dulcimer tuning. Ionian / DAA allows Dan to play major scale melodies and chords but also to play minor chords to accompany a minor-scale song. There are also other chord families, proving the rich harmonic potential of the dulcimer in Ionian.
Dan exploits this harmonic potential by finger-picking chords to accompany his fine baritone voice on folk songs. He also arranges songs as instrumental airs in Ionian.
other dulcimer tunings Dan uses
The Dorian mode (DAG) conjures up a strong sense of the medieval on the dulcimer, Bagpipe tuning (AAA) gives a rich sound with either a major (Ionian) or a Mixolydian scale and the Aeolian mode (DAC) is sometimes used to evoke a sense of the Elizabethan period.
From influences page:
[T]wo wonderful guitarists that still inspire me are the French Pierre Bensusan, who specialises in playing jazzy guitar ‘landscapes’ in DADGAD tuning and the multi-award winning folk guitarist Martin Simpson – indeed the only instrument training I’ve ever had was an informal one-to-one session with Martin – in just fifteen minutes he transformed my playing, helping me to put power and poise into my right hand technique – both Pierre and Martin are enormously deserving of their success and recognition in the guitar world
dulcimer I’m deeply indebted to the late, legendary British dulcimer player, Roger Nicholson – Roger’s transcriptions of medieval lute tunes for the dulcimer are second–to-none and he has inspired players on both sides of the Atlantic in so many ways – Roger and I made a trip to the USA together and we recorded a couple of dulcimer duets on my Spirit Dancing CD – Roger was not only inspirational to me but he also encouraged and helped me in my own career
Nashville-based Stephen Seifert is also a friend and is probably the leading player in the world today – he was the protégé of the late, great David Schnaufer, whom I had the privilege of getting to know on my first trip to Kentucky – Steve’s playing totally transcends the instrument, which becomes putty in his hands - jamming with Steve when we meet up at festivals is both a delight and an education