Well, I suppose I will start with describing my current thoughts on "musicianship" as how one relates with music, and a "musician" as one who relates with music. I personally would not describe a "musician" as one whom creates music (nor would I describe a composer as such, for that matter). This is an important distinction, I believe, because in that sense of relating with music, I see everybody as a musician of sorts. Everybody has some kind of relationship with music whether they are choosing it or not, even ignorance is a type of relationship (and I personally believe it is human nature to be forever ignorant of itself and its endeavors).
A person who sits down to compose, at whatever stage in the game (and with whatever tools), is learning about their relationship with music whether they are acutely aware of this or not; they are exploring their musicianship.
Exploring our musicianship, I believe, is most likely our highest possible attainment within the field of music. What people think of as "formal training", at its best, can only help to focus that musical exploration (or hamper as the case may be) and I do not see training vs intuition as a call of value on, nor summary of, one's musicianship-- relationship with music-- in and of itself.
So, in short, yes I do think that s/he is a musician.
m1469