GMM are extremely fortunate to have Mike Jewitt as our musician.  Mike has played has played for several other sides.
Mike's first instrument is the accordian which he plays with style.  Thank you Mike!

Most people (well at least Colin, Bill, Paul and Ged) agree that "squeeze box" Morris music is best played on a "diatonic" instrument.  This means that you get two notes per button according to whether you are pushing or pulling.  This gives the music an inherent rhythm.
(Imagine having two mouth organs joined by a bellows).
Mike is currently hohnering his skills on a diatonic instrument -
 a melodeon, similar to The Squire's.

Bill and Ged also play a diatonic instrument: the Anglo Concertina.