// When adding to this array, always insert sub-array elements in the order they have been observed
$validLengthGroup = array (
	array(6,5,5),
	array(3,3,2),
	array(8,3,5), // a very poor and problematic representation of a triplet, but it does occur e.g.
		      // with triplet (crotchet, crotchet rest, crotchet)=(8,3,5). However, in the quaver version of this
		      // example the rest has disappeared altogether (3,NULL,1). so we have no chance!
	array(1,2,1), // another poor one, included to cope with Lawrie's test file
	array(11,5),
	array(3,5)
	);