There is very little in the owners manual about USB drives so I have been learning by trial and error. I have a Mac and all my music was m4a for itunes and my ipod. The Frontier will not play m4a unless it is on an ipod, it will not play them from a USB. I let Apple Music convert all my music to mp3, it will only convert them to 192kbps. If you want the 320kbps, you have to use another program like audacity and that is a song by song conversion, I don't have that kind of time (I do but I'd rather take a nap). I use the scandisk cruiser fit in both 64GB and 32 GB size, both way bigger than necessary. These are the tiny drives that only stick out about a 1/4" so they blend in with the dash.
I made folders for playlists instead of for albums or genres. To each his own. With the USB on, I found that I can touch the USB Menu button on the upper left hand corner of the screen. Then touch the folder list button in the same location. Now I can select the folder (playlist) that I want. When I touch on the top song, it starts to play and it goes back to the main screen. This is where I had the biggest issues. I want the playlist to shuffle the songs so I touch the shuffle button, what I didn't notice is that under the shuffle button, it will say either "all" or "1 folder". All comes up the first time you touch this button and that causes the system to shuffle through all the folders. You have to touch it a second time so that it says "1 folder" under the shuffle icon for it to stay in that folder.
I haven't tried sub folders yet so I don't know if they will work.
I made folders for playlists instead of for albums or genres. To each his own. With the USB on, I found that I can touch the USB Menu button on the upper left hand corner of the screen. Then touch the folder list button in the same location. Now I can select the folder (playlist) that I want. When I touch on the top song, it starts to play and it goes back to the main screen. This is where I had the biggest issues. I want the playlist to shuffle the songs so I touch the shuffle button, what I didn't notice is that under the shuffle button, it will say either "all" or "1 folder". All comes up the first time you touch this button and that causes the system to shuffle through all the folders. You have to touch it a second time so that it says "1 folder" under the shuffle icon for it to stay in that folder.
I haven't tried sub folders yet so I don't know if they will work.
