In fact, this is what the user manual recommends, the ability to transfer MP3 music to the camera from a computer (Windows or Mac) using the USB cable supplied.

Directly as already described, or load MP3 files directly onto the SD card with the computer, if one has been purchased and a corresponding drive is available on the PC.

Connect the camera via USB. On the computer/Mac it is then a drive onto which you can load MP3 files, for example.