Ubuntu Multimedia :: Transferring Music To Sony Walkman NWZ-S545

I have a Sony Walkman NWZ-S545. I have Rhythmbox 0.12.8. I have a System 76 amd64 computer. I have run Ubuntu (now 10.1) for a couple of years and before that Linspire and haven't had MS Windows for years.

What I want is to be able to simply transfer music files from my computer to the Walkman. Nothing fancy. Drag and drop is fine. (I was hoping that it would be shown on the desktop, that I could open it and access it and drag files to it.)

I looked in Ubuntu help and found: "Ubuntu will work with most portable audio players, including iPods. Normally, all you have to do is plug the player into your computer and then use Rhythmbox to copy songs to and from the player."

When Rhythmbox didn't recognize it and no icon appeared on my computer screen indicating it was plugged in as an external device, I went back to Ubuntu help and found and installed the mtpfs and mtp-tools packages and made sure that the MTV plugin in Rhythmbox was checked. Now Rhythmbox could see the Walkman BUT could not play any songs! And there was no Walkman icon on the desktop.

When I tried to play the 5 sample songs on the Walkman, I got one of these 3 errors:
a. Couldn't start playback - no file name specified for reading
b. No URI set
c. Unable to copy file from MTP device: PTP Layer error 02ff: LIBMTP_Get_Filemetadata(): call to ptp_mtp_getobjectpropssupported() failed.

(BTW, my Rhythmbox setting under preferences - music is for .ogg - can see other options under edit but cannot switch to them. My mp3 songs transferred from my external hard drive to Ryhthmbox beautifully and play just fine)

After further searching, I read I should confirm that libmtp8 was installed and I found that it was.

So I went to Ubuntu Rhythmbox help and read: "If Rhythmbox Music Player does not detect your device as a portable audio player, you can create an empty file named .is_audio_player at the top level hierarchy of the filesystem of your player."

OK - I am stuck here at several levels:
1) Is this what really needs done?
2) If so, how? (I searched ".is_audio_player" and came up with several comments and how-tos, all seeming to involve going into the root directory and inserting an empty file somewhere. First of all, I can't get into my root directory even as the administrator with full privileges! Secondly, I know enough to know that even if I could - I shouldn't!