Randy,
As I stated earlier in the thread you are assuming that the producer has to be capable of "playing and instrument" to be a musician. This is not true and is the basis of my observations earlier.
Singers are musicians, conductors are musicians and people who have a high level of understanding of music and form are musicians if they use that skill to help create music. (see my poost earlier in this thread with the definition of a musician from a couple of disctionaries).
SO even in your scenario I advocate that the producer must be a musician to provide the functions you describe.