After playing around with the Neo-22 for a while, a few observations on USB use:
1. USB File format should be FAT 32 and max USB size 32 GB
2. mp3+cdg zipped files DO NOT play. mp3+cdg unzipped files DO play and are sequentially numerically labelled by the neo-22 in the order that the files are listed in the FAT 32 directory on the USB Memory Stick. If you want to insure that the file names are sorted in alphanumeric order in the FAT32 directory on your USB Flash Memory Stick, Download the Windows program "DriveSort" (currently v 1.223) which works OK on my windows 8.1 computer.
3. Although it may not have been necessary, I converted my several hundred MPEG2 and MPEG4 karaoke videos to MPEG1 (Video CD) Format. The neo-22 does play these mpeg1 files from the USB stick. I then loaded these files on a different USB memory stick from (2) above and sorted the file names in the FAT32 directory on the stick in alphanumeric order using DriveSort. On a spreadsheet, I sorted the songs by file name and then, starting with the number 1, sequentially assigned numbers to the songs. The assigned numbers can then be typed in on the neo-22 remote to select a particular song. I used this same procedure to assign numbers on a spreadsheet to the mp3+cdg songs in (2) above.