Devaney's Goat is one of the many compositions of Eddie Moloney, a flute player from the Ballinakill Céilí Band. The tune is often played in C Major and may have even been composed in that key. However the version that Tony plays is in D Major.
The tune is fairly compact for the fretting hand. Being in the key of D, there are no notes on the first fret, so use the first finger for second fret, second finger for the third fret, third finger for both the fourth and fifth frets, and your fourth finger for the high B on the seventh fret in Bar 1 of Part B.
Tony plays some of the B notes in Bars 1, 3, and 5 on the fourth fret of the third string rather that the open second string. The reason is that it makes the right hand picking easier, but you can use open B if you so choose.
If your fretting hand is correctly aligned to the fretboard, that is “square” to fretboard, then you should not have to move your hand to reach the high B. Wherever possible, stretch the fingers rather than moving the hand.
Tony says you should always look to add a few ideas of your own into a tune. Whilst performing in, for example, a baroque or classical string quartet may require you to “stick to your part”, in Irish music you are free to add or even sometimes omit notes.
The chord progression is identical in both the A and B parts of the tune. This is not uncommon in traditional music.
Chords are D, G, Em and A.