How does a song get stuck in your head?

Whether it’s a doot doot doot of an opening riff or a random mix of words from the chorus, 99 per cent of people admit to getting songs stuck in their heads. So what is it about certain songs that make them so catchy? How does a song get stuck in your head? For transcripts of this series, please visit: https://www.cbc.ca/radio/podcastnews/tai-asks-why-transcripts-listen-1.6747759