Polish in origin, mazurkas are not very common in Irish music.
Sonny’s Mazurka is arguably the most well known of the mazurkas played in Ireland.
As mazurkas are written in 3/4 time the rules that you use for waltzes also apply to mazurkas. In this tune most of the bars have a crotchet on the first beat followed by two groups of quavers over the next two beats.
As an accompaniment, a basic strum consisting of a bass note on the first beat followed by full or partial chord strums for each of the next two beats in each bar would be quite sufficient. In other words treat your accompaniment the same way you would a standard waltz.
Note the B Minor chord in Bar 3 of the second part of the tune. D would be quite acceptable but B Minor just sounds a bit nicer to Tony’s ear.
Chords are D, G, A and Bm.