There is this program: https://techmadeplain.com/2014/how-to-sort-music-flash-drive-car-stereo/
I have used it and it works well. The other option, which I have done, is to place all of your music on your computer; then erase the flash drive and transfer it back from the computer to the flash drive.
I have used it and it works well. The other option, which I have done, is to place all of your music on your computer; then erase the flash drive and transfer it back from the computer to the flash drive.