I tried a writing course a couple of years back just for something to do. I was dubious and concerned about mixing with the muse.
What I found, was formulaic, cynical, rules based and lacking in creativity.
I was very recently asked to prepare an outline (curriculum) for a songwriting "course" (I prefer the term "workshop". The Cultural Center in my community reached out to me since I attend a monthly "songwriter's meeting" (in which some local songwriter's share our material and if/when appropriate offer encouragement, critique, etc.)
Since I've had some small "commercial success" as a songwriter (being published with songs in a couple of movies, a TV show and a few indie artist recordings - as well as composing cue music for a couple of local indie films and industrial training videos, etc.) - I guess I am perceived as someone with knowledge and insight.
For the last couple of weeks I've been reading numerous books related to songwriting (some I previously read and some I've owned but never looked at). As I review and organize the data in a way that is not open plagiarism - I've come to certain conclusions:
1. You can teach the basic concepts of "songwriting" as applies to certain recognized applications (going all the way back to "Tin Pan Alley", the Brill Building, etc.) of rhyming schemes, song structure, etc. And I believe you can teach some fundamental concepts related to melody and rhythm.
2. You can teach how the use of those concepts can be used to "improve" songwriting in a manner which while some would argue is safe and formula driver - can indeed improve the potential for the song to meet certain "criteria" that most publishers are looking, for
Note: The debate if this equates to a "good" song or making a "good" song "great" - is something that pundits can debate into eternity - but it can improve the potential for getting a song published
3. You can teach techniques for finding clever song titles, hooks and other songwriting "tools" that can improve a writer's ability to create a solid song.
4. You can teach the business aspects of songwriting (how to present demos to publishers, how to interpret publishing contracts, etc.)
5. You can not teach passion nor can you teach how to create a song that can touch another person
Personally, I see nothing wrong with songwriting courses, workshops, etc. - if the instructor is reasonably knowledgeable and can present the information in a qualified manner. However, it does depend on what the writing is seeking. If the writer is hoping to achieve some level of "commercial success" then some things can be taught/learned - however, if the writing in only interested is serving his/her own artistic desire with no interest in trying to create an income producing craft - then there would be no value for that writer to try to acquire any additional "knowledge" about the formula driven concepts of writing.
On a side note, my mother-in-law is a well respected writer, with several 3 act plays that have been performed around the world and with two published novels. For many years she taught writing at a local community college - and she and I have discussed the debate about trying to "teach" writing. Regardless if the media is song, book or play, the concept remains the same - you can teach commonly recognized techniques - but you can't teach passion or creativity.