Katie Gregson-MacLeod´s “September” reflects on the complexities and changes within a relationship and the realization that it could not last. She transmits longing while contemplating a past love that was intense but ultimately fleeting. The composition deploys a narrative of romantic nostalgia and reflection on a past relationship. The song appears to be about the narrator’s feelings towards someone they were once deeply in love with and the complexities that came with that love.