Music is recorded, mixed and mastered using speakers. Recording studios have calibrated monitoring systems that present the sound in a consistent manner. The speakers are measured in the room to precise standards. The reason music isn't mixed and mastered using headphones is because there is no way to consistently calibrate frequency response using headphones. The shape of an individual's ear canals significantly affects how headphones sound. The same set of headphones can sound different to different people. This isn't true of speakers in a calibrated studio environment.
If you want to hear music they way the artists and engineers heard it, build a speaker system to as close to studio standards as you can. If you want to listen using headphones, EQ to suit your particular ears.
The Harman Curve is an averaged response curve based on preferences of a wide range of people. That's a great place to start with EQing your APMs. Here is pretty close to Harman using the iTunes equalizer.