"The Poet and the Muse" is just one of the songs by the fictional rock band Old Gods of Asgard in Alan Wake.
Alan Wake is a psychological thriller following a writer who becomes caught up in a real-life mystery in the small town of Bright Falls. It delves into the supernatural and plays with a loop whereby certain peoples' writing can alter or recreate reality.
In this sense we never really know whether Alan ended up writing the band into existence or whether they perhaps wrote him. The song is very clearly about the overarching narrative of Alan Wake. It references Thomas Zane ("Tom the poet") and Cauldron Lake ("the magic lake which gave a life to the words the poet used").
It then outlines Alan Wake's own experiences, attempting to "bring back his love by stories he'd create" after she was taken by the darkness. Yet at the same time the song provides advice and instructions as to how to achieve this through finding the "lady of the light"; things that Alan doesn't necessarily know about when he can first hear the band's music.
With a whole in-game band history which becomes instrumental to the game's outstanding narrative, not to mention a discography of albums, The Old Gods of Asgard are in a very unique and central position within the game.
"The Poet and the Muse" is full of prophecy and supernatural themes; a musical microcosm of Alan Wake's core ideas. On top of this, it's a genuinely good song, with a great chorus, fantastic evolution from acoustic to full rock sound and deep, meaningful lyrics that tell a story even when separated from the game.
In our reality, the songs were in fact written and performed for Alan Wake by the real-life Finnish band Poets of the Fall.
With the questions Alan Wake raises, though, who's to tell whether we are in fact in the story?!