I'm 99% sure it's by Christina Aguilera. It's one of her earlier songs and the music video has a window and like a dark black or grey background. It's one of her first hits and it starts out really bluesy and slow with a pentatonix scale and it's really low at first but then there's a key change and a bunch of crazy runs and high notes at the end. It's an "I remember him" type break up song and literally the only lyrics I can remember is "I visualize" and "remember" PLEASE PLEASE PLEASE HELP ME!
Most Helpful Girl
Check if it's "fighter" x0