Natasha Romanoff doesn't have her own theme music unlike some of her fellow MCU heroes, but that's somewhat fitting for a character who expresses her struggle to tell her own story. It's obviously not the first time the MCU has used chart tracks, with the Guardians of the Galaxy movies introducing the Awesome Mix tapes to the franchise and other notable examples dotted around like Eiffel 65's 'Blue (Da Ba Dee)' in Iron Man 3.
Like all MCU films, Black Widow has a great score to back up its story of intrigue, abuse, and triumph over adversity, but the soundtrack also includes some pop music tracks. Warning: This post contains spoilers for Black Widow.