For Spotify music, generally, you can't use them on your music player directly. But now there are lots of tools like DRmare Music Converter that can help you. With such tools, you can easily download and convert Spotify songs as local audio files. And you can get the Spotify audios with original audio quuality for offline listening. Then you can save the Spotify music files onto your computer and move Spotify music to music player or other devices for playing offline.
To get more info, please go to https://www.drmare.com