|Says William Congreve, Wigged Whig, Misquoted Beast, & Turner of Phrases|
Bravo, La Novella Baroque!
What does all this have to do with mythopoesis, you ask? Well, how often do you consider what kind of music would populate your world? It is another detail of world-building that can add to the sense of secondary creation. For example, the musical explosion of early baroque represented an achievement of musical technology, the maturing of a long history of earlier musical traditions, and cultural interactions in a context of political unification and conflict. It would take a similar setting, not necessarily with the same level of technology in other areas, to support this advanced, courtly art form. Thinking about music in the various areas of the setting is of a piece with the structure as well as the character of that part of the setting. Music can also be tied to characters: closer to the inspiration of this post, consider the musical component of Patrick O'Brian's Aubrey and Maturin.
Finally, if you have never listened to music while brainstorming, writing, or preparing (especially instrumental music), give it a try. Different choices of music can make for great inspiration.