[heja2009]

> How did Wagner justify his music in philosophical terms? Why did he even feel the need to justify it? What would such a justification look like? What would a competent justification look like? How can I identify a composer who has philosophical gifts?

Wagner (and most other composers) were highly influenced by their contemporary philosophy. The wikipedia article lists a lot of this and Wagner is a very good example for this as he had rather intense and highly influential conversations with philosophers: many books have been written about Wagner and Nietsche's relationship alone. Wagner also changed his ideas (and consequently his music) over time, most prominently embracing first germanic mythology and later christianity.

About the "competence" and "half-bakedness" of musical theories held by composers over the time you can probably entertain many prolonged spirited conversations. Personally - having read some classical and pre-classical aera musical theory books - I think you can find excellence and mediocracy distributed rather equally over the centuries.

And yes, this piece seems to expect the reader to know a bit about music history, especially that of musical theory.