Hello all,
First a disclaimer: This requires root access (aka root your phone) to get working. I cannot be responsible for anything that happens.
Today I am happy to tell you I have a tested working solution. You can now use the USB and voice commands to control music from the external microSD card.
1) You have to root your phone.
I am not going to go into details on this there are plenty of sites with tutorials. Its really quite easy. Only took me 5 mins. Google Odin.
2) You will then have install busybox, this provides unix tools for installs.
3) Install "SG USB Mass Storage Enabler"
4) Open "SG USB Mass Storage Enabler" and set it to "Mass Storage Mode"
Thats all there is too it.
Note: I have a 64 GB micro SD card, and was formatted in exFAT and I believe most 64GB are. The exFAT format does not work with the USB Mass storage so you will have to format it to FAT32. There is a good program called easeus for this. Not sure of all the formats that will and will not work, but I know FAT32 works.
Second Note: I did upgrade my firmware to the latest as I was not having any luck getting it to work but this was prior to formatting the card. After the firmware upgrade did not work, I formatted the card to FAT32 and it worked, so you might not have to upgrade, but just wanted to mention it.
Thanks all,
and goodluck.
Ramsdaro