All you need to do is place music inside any of your music folders and tell talkhouse to rebuild its index. Just press the ‘build index’ button on the Collection Panel and the index will be rebuilt.
If you’re only adding a few new files and you want to add them quickly without reconstructing your entire index then just drag them on top of the player. They’ll be added in a few seconds. Don’t be concerned that this will make additional copies. It won’t. It just lets the Talkhouse media player know that new music files exist and and where to find them.