I can't say much about the DInc but the Bionic has internal storage in addition to the Micro SD card. If you go to your file manager ("Files" program), you'll see that there is "internal phone storage" and "SD card".
You can put your old SD card in, move those files to your internal memory, swap the cards back and then move your music back to your Micro SD card. Depending on how much music you might have to do this several times as you don't have as much space available on your internal memory as you do your MicroSD card. Frankly you're better off getting a couple of Micro USB cables and doing it that way.
One other note, in the phones file system, you'll see "/sdcard" and "/ext-sdcard". It's a little confusing, but "/sdcard" is your phone's internal memory and "/ext-sdcard" is your actual Micro SD card. I believe that they did it this way to allow apps to use the faster internal memory by default instead of the MicroSD card. It is also for this reason I would recommend putting your non-essentials (music, photos, etc.) on the Micro SD card rather than internal memory.