Much like in Spotify where you can choose a song then click the three dots to "add to playlist" and then select which playlist(s) you would like to add it to, a similar feature could be very helpful in the main "All Media" library so you can add content directly from this area to your playlist. The small dropdown Library under the filmstrip in classic playlists is overwhelming to sort through in large organizations and the folder view isn't as intuitive to browse through.