Well, I've taken to heart a few owner's commenting on how fun it is to play with the USB port delivering music files to our Oppo's.
Fun would not be the first word starting with "F" to come to mind right now.

The manual is a bit thin, but I read and (I thought) understood what it had to say. Called Oppo (guy picked the phone right up yesterday) and asked about file formats and bit rates. MP3 and WMA, any bitrate no problems according to the TSR. Doesn't do lossless, will play via folders. OK
So, did a trial with two folders on flashdrive. One labeled "Zselect" and empty, other labeled "Chris Botti" and holding 12 or so MP3s at 192kpbs. Couldn't seem to make anything happen without patience, and then almost accidentally selected the folder and got tracks to start playing. I thought that I had done the exact same thing a couple of key-stabs earlier without result, and suddenly got sound. shrug. Entire folder played through without problem.
So tonight, I loaded some music into the root directory of the same flash drive. Chose USB via OSD, selected to 1st track and pressed play. lights continue to flicker on flashdrive for many minutes. Never plays a note. Id's the song via text, including artist, time and bitrate (359kpbs via WMA variable), just keeps flickering lights forever. So, I try to revert to the "Chris Botti" folder used above, able to scroll up to that folder, but when I actually select it (to open, I guess), NADA. Flashdrive keeps flickering to beat all-get-out. Nothing ever changes over almost 10min.
grrrrr! I either don't have a clue of what I am doing vis-a-vis music files via USB (so, who'd have guessed that!

) , or I am doing the simplest of things wrong in my switcholgy on the Oppo. I am perfectly willing to accept either, if accompanied by sage advice wielded by stout souls withOUT baseball bats.
This is truly my first attempt at this endeavor with any device. I just ordered a rather cool 13th B-day present for my kid, and knew that I needed to glom onto a bit of new knowledge to help her put the Yamaha TSX-140 through its paces. Steep curve----Old Dog.

Mkard