I can use iSync with bluetooth, but only for my phone contacts. Not for files. It also fails immediately every time I try to use Bluetooth File Exchange. The only way I found to get music on my phone is to:
1) Put the micro SD card into the phone (with the phone powered off, of course)
2) Turn the phone on so it will set up the necessary folders
3) Take the card back out of the phone and load it into an adapter and put the songs directly into the micro sd card.
For me to do this, since there is no SD card slot on a macbook, I loaded it through the multimedia card slot on my printer. A little frustrating to have to go this far just to listen to music on my phone. Btw, I don't think it necessary to go to extreme lengths to try to get music loaded directly to your phone memory. It'll only hold about 4 songs. I say forget it. Get an iPhone 😉