Tried to play some music files from an external USB source and received the subject was no installed.

l need to find a source for use with Ubantu 18.04 where I can down load & install the files.

Regards, James LeMay

would be nice to give more information. What OS do you have, how did you try to play that file?
Probably VLC can do it for you.

There should be no problem playing music files from an external device. Not sure what your reported error messages means or what "subject" is referring to. You should have some software in a default install to play music files but what type files are they. What files are you wanting to download? Are you referring to software to play music files? Ubuntu repositories would be the best place to look. I'm not sure but I don't believe VLC is installed by default but should be in the repositories. More detailed info would be helpful.