+1 about electrostatics. But even though my Sound Labs get down to 30Hz, they can’t play those lower frequencies at a decent volume, so I added a subwoofer.
To OPs question, think of the surface of a pond that can have different sized waves crossing at the same time from different directions. Your speaker cone is like the pond, vibrating lower frequency waves and high frequency waves all at the same time. The speaker can do that. That’s what music is. As others have pointed out, the quality/accuracy of the sound reproduced by a single cone driver is debatable.