You wake up, and before your brain has even warmed up, it starts to play that same piece of a song over and over.
More than 100 years ago, Germans coined the term Ohrwurm- earworm - to describe the experience of a song stuck in the brain. Once they start, these little musical memories can repeat uncontrollably for hours, days, even weeks at a time. A few unfortunate people have reported having a song stuck in their heads for a year or more. Research indicates that nine out of ten people have experienced earworms that have lasted for an hour or longer.
A researcher from the University of New South Wales has found that earworms (or involuntary musical imagery), make their way into our brains when we are relaxed. Certain songs are more successful not because they're 'catchy', but because they're repetitive which makes it easier for our brains to become familiar with them. The implication is that earworms might not have anything to do with the musical features at all, as long as repetition is part of the song's structure.
The auditory cortex is where earworms do most of their karaoke. This is the part of the brain that does most of the processing of sounds, it is also where musical memories are stored. 'We found that the auditory cortex that is active when you're listening to a song was reactivated when you just imagine hearing the song' says researcher David Kraemer.
So far, no one knows why songs sometimes get stuck in our minds. You might be able to shake off an earworm by deliberately focusing on another tune, or completing the entire piece in question, not just the catchy part. Maybe sing the whole song to your colleagues tomorrow morning?
Either way, you would be best to just accept it rather than attempt to block it out. Any type of resistance may result in the very opposite of what you want. In most cases earworms are pleasant, and could even be part of your brain's creative process.
Which song have you had stuck in your head lately?