I want to add about 300 songs as a playlist. Some are already in my library but many are not. Can I do it without having to add them individually?

I want to add about 300 songs to my database and have them as a separate playlist. I see that it is possible but I don't see how it's done. Also, some of the music is already in my database, does that matter?

Sorry, I'm sure this is soo basic. I am looking for the duplicates node and it tells me its in the library. I don't see library anywhere (only maintain library). Do I need the gold version for this?