In conclusion, it can be said that research on musical development focussing
on a single aspect has its advantages (depth) and disadvantages (isolated). In
contrast, regarding of musical development in stages might be compelling,
as it gives an orderly overview of development, and with it, the idea of clarity
and transparency. The question is, however, if (any) development occurs in
such a step-wise manner. A succession of stages admittedly creates a clear
picture of development, but that lucidity might be too good to be true, for
children usually do not tend to develop in an ever-rising line, nor do they
collectively reach the same levels simultaneously. From that point of view a
stage model for musical development certainly has its disadvantages, unless
the concept of stages linked with age is not regarded of as rigid
(ontogenetic). Accordingly, from their research, Davies (1992) and Marsh
(1995) claim that children can be at different stages in their musical
development simultaneously, which is something I recognize in my
experiences as a (music-)teacher as well.