If you'a an iPhone user, you can use iTunes
to transfer music from iPhone to computer first. You may have well known that iTunes only transfers purchased items from iPhone to iTunes library, so iPhone users can move purchased
songs from iPhone to iTunes library.
- Run iTunes and click "Edit > Preferences > Device > Prevent iPhones, iPods and iPads from syncing automatically" at the upper left corner of iTunes window.
- Plug iPhone into computer via the USB cable, and then click "File > Device > Transfer Purchases" at the upper left corner.
- iTunes will start to sync all the purchased items back to its library.
After the syncing process, you will get the music files in your iTunes library, including the purchased music files. You are able to find the music files in the folder of your iTunes media files on your computer.
The next step is really easy. Since the music you want is already saved on your computer, you can now simply connect your MP3 player, drag and drop to transfer songs.
On the contrary, here's also a guide about Three Ways to Transfer MP3 Files to iPhone
in case you need help.