Vic Smith: just to be irrelevantly technical, the majority of Cajun music is played in G but the accordion is a actually a C one row, played "backwards" in G(like cross harp blues playing on a harmonica, when players almost invariably use a C harp to play in G. This trick of playing backwards enables you to play tunes in A on the D row of a D/G melodeon, which is well worth mastering.