Inspiration...How Important is It?

I like to think that I am a writer that is led by inspiration. I can't just pick up a pen and start writing. If I wrote without inspiration, it would make absolutely no sense and the story won't flow. I prefer to have some sort of inspiration for the piece and then inspiration that keeps the story flowing.

For example, I wrote a YA romance piece. My initial inspiration for the piece was a bible verse and I expounded and fictionalized the verse to the point you wouldn't even know the piece was from a verse from the Bible. To keep me on track with the romance element of the piece, I listened to A LOT of Taylor Swift (Back to December, Our Song, Story of Us), The Cinematic Orchestra (Arrival of the Birds, Transformation), Yiruma (A River Flows In You), among other songs that my brain registered as romantic. For some reason, I desperately needed the songs because they put me in the mood to feel what my characters were feeling at the moment in the story.

Even now, I am listening to Switchfoot Dare You to Move over and over while writing a military piece. The beat makes me think of a soldier climbing through sand dunes to do his job so he can get back to his family. The song puts me in the mood to write about my main character.

I wonder how important inspiration is to truly connect to a story. Is it important at all or purely optional? Does the setting of the author help the setting of the characters in the story?