I use a file manager to manually move music, pics, videos, and other data files from the internal storage to the external SD Card.
Some Android phones have a file manager already installed. My Droid 3, had the app 'Files' that works well for moving music, pics, videos, and other data files from the internal storage to the external SD Card.
My OG Droid did not have a file manager installed. There are several very good ones in the App Market. When in the App Market, do a search on File Manager. Try several and pick the one that works best for you.
I have used ES File Manager, OI File Manager, Linda, and Astro. Each has their individual strengths. There are also others that I have not tried; one of them may work better for you. Give them a spin.
Bob