Choosing an accordion for Irish music II - voices, tremolo, action

What multiple voices do and how - medium or clarinet voices (M) and low or bassoon voices (L). Examples of MM, MMM, LMM, LMMM and different tunings or tremolo. Why the two rows have a different tone. How tremolo takes the hard edge off chords in equal temperament. Version avec sous-titres français:    • Accordéon irlandais - quel instrument choi...