The Dg box is a great rhythm box and here are my thoughts on adding layers of rhythm to which hopefully others will add to, agree with, disagree with or whatever!
To me there are in essence 4 ways of creating rhythm which can be used singly or in any combination depending on the tune being played and the desired effect.
1. Playing the melody line rhythmically. The basic rhythm should be inherent in the way the melody is played in just the same way as happens on melody only instruments such as fiddles, whistles etc. Every tune has or should have an inherent rhythm including slow airs and it is that basic rhythm that is essential in transforming playing the right notes ion the right order into music!
2. Using spare fingers to beat a rhythm additional to the inherent rhythm of the treble, The extra rhythm can be extra single notes or right hand chords or a combination of the two. This is quite easy to do as on the push any combination of notes will harmonise and on the pull there is only one combination that won't
3. Intermitant GENTLE pulsing of the bellows to add a fairly unobtrusive extra layer of rhythm here and there in a tune particularly bits where the bellows are going in one direction for a few bars of music. This is not to be confused with bellows shaking that some piano box players indulge in.
4. The bass , preferably played lightly and crisply and not necessarily consisting of um pa ing throughout the proceedings. Sometimes less is more and leaving the bass off for a bar or two here and there can add to rather than detract from the overall effect. With some tunes at opposite ends of the speed spectrum leaving the bass rhythm ( but maybe or maybe not keeping sustained chords) can help eg in haunting slow aires or very fast jigs and reels.
please feel free to disagree or otherwise criticise this list or preferably to chuck in some more 'layers' of bass???
george