Diegetic Music

I just learnt a new term, diegetic music, defined in Wikipedia as:

music that is part of the fictional world portrayed in a narrative (such as a film, show, play, or video game) and is thus knowingly performed or heard by the characters. This is in contrast to non-diegetic music, which is ... heard by the viewer but not the characters, or in musical theater, when characters are singing in a manner that they would not do in a realistic setting.

Off the top of my head, here are my top three instances of diegetic music in movies.

The group singalong to Tiny Dancer from Almost Famous (2000):

The swing scene from Satyajit Ray's Charulata (1964) – Madhabi Mukherjee singing Phule Phule Dhole Dhole (ফুলে ফুলে ঢ'লে ঢ'লে):

I've loved that scene since I first saw Charulata in high school, but now it's also entwined with the memory of my friend Rajasi (whom I've mentioned before) singing on the public swings at Kim Pong Park.

And finally, Faye Wong in Chungking Express (1994) secretly cleaning her crush's apartment while playing California Dreamin' on his CD player:

California Dreamin' is a recurring motif in Chungking Express, but my favourite song from the movie is Meng Zhong Ren (夢中人), sung by Faye Wong herself – a Cantonese cover of Dreams by the Cranberries. However, Meng Zhong Ren is used non-diegetically, as background music, and is thus not eligible for this list.

By the way, this is a cool video about how Wong Kar-wai made Chungking Express almost as a side quest. As teeveetalker puts it:

Chungking Express was made on a shoestring budget, with no permits and a constantly changing script. Made like a student film, it comes with a young project's optimism, experimentation, bravery and inherent coolness.

Sure, it has flaws – "If you're trying to follow the plot, you may feel frustrated," wrote Roger Ebert, while Janet Maslin was unimpressed by its "raffish affectation" – but for me, the flaws are part of its charm, and therefore, its strengths.