Option 1: Transferring music via USB cable
This is the most common variety to music on the Samsung Galaxy S6 heard. Just close to your smartphone via USB cable to the PC. You can now access the internal memory of the Samsung Galaxy S6. Created there a folder with music. In these you can now copy your MP3 files. The smartphone will then automatically detect the built-in Android by Media Scanner the newly transferred songs.
Option 2: Transferring music via Cloud
Should you have your music stored in the cloud such as Dropbox, then invites you on your Samsung Galaxy S6 the app "Dropbox". About this then you have direct access to your cloud files.
option 3: download music on Google Play Music
Google Play Music is pre-installed on any Android smartphone. Once logged in, you can listen to music and download. A huge selection of music is get ready in this portal. The good news: You can Google Play Music 30 test days for free, if you have never used the service. Definitely worth a recommendation. Your now has three different variants to hear or to transfer earlier music on your Samsung Galaxy S6.