I applaud Allen's efforts on this production, without going into specifics which I think chas laid out pretty well ... I have used the midi sequencer on the KB to change some 'styles' by replacing voices and overwriting accomp parts, so I know that it can be a time consuming project at best ... as in many cases, the procedure is relatively easy, but the execution is sometimes quite challenging ...
Personally when I perform this song - usually only at St. Patrick's Day gigs, unless otherwise requested - I prefer a simple acoustic style with a guitar arpeggio or something similar ...
When we had the band in NY, our featured vocalist - a fine Italian gentleman (but then the 5 of us happened to be Italian ) would sing "Danny Boy" and we would give him minimal background, with no strict tempo ...
But, it's all a matter of personal preference ..