Lately I stream live on YouTube. While doing so, I play music. Every time I begin a stream I play the same song, the rest is random (shuffled).
The idea is that people get used to this, and start to associate the song with my stream(s). Hopefully even get a good feeling because of this recognition (Kind of like the smell of coffee is associated with a cozy time).
At some point I wanted to say
I guess this is my ______ song.
But couldn't find the word. The only thing that I could think of is "theme song", but that just doesn't fit what I was looking for. Is there another word that more closely describes such a tune or song?