Thanks everyone for your input.
I used a windows formatted mem stick with some music folders added in a folder called music - with nothing else on the stick.
As far as playlists go selecting tracks copying to a new folder named playlist or whatever would work.
The Honda USB music app seems to work ok.
Repeat and shuffle, an ability for me to search folders and select some music.
But still need an answer to getting Bluetooth audio to access music on the SD card.
As it was said above, then I can connect my phone to Android auto, which incidentally seems to work ok now, although, I am on my third lead, or maybe it's updated.
Since writing this reply I did some research on Android Auto.
Within the settings of the App on one's device ( Honor 7C) we have to select which apps will be visible when connected to the Jazz.
So before connecting I choose a media player ( VLC) opened it and let it detect my music from the SD card.
Then, in settings, I configured Android auto to display VLC then connected to the car and it sees VLC and I can use it to play music. It looks at first light that if music is in lots of folders it might play one folder at a time then need manual input. ( Not tried Google assistant yet). However, shuffle play seems to work.
I then selected maps and the display changed to navigation and music continued.
What I thought was good was it showed title and artist as play started on the main display status bar and on the instrument panel.
So will probably not bother with Bluetooth audio.