Why does anyone still directly load music to their phone/SD Card? Upload it to Google Play Music, put it in a playlist and pin it from there. Voila! Music loaded on your phone.
It is accessible from Android and iOS devices and also any laptop or desktop computer, there's almost no chance that you'll lose your music and it is incredibly convenient. And you can load up to 20,000 songs for free!
And before someone comes back with their "but my collection is way bigger than 20,000 songs" complaint, clean up you collection, no one has more than 20,000 good songs, what you have is a bunch of junk taking up space.