I'm hearing a song and thinking to create a new playlist.
If you start with the screen with all your records a double touch on one cover of a song to mark this song for a playlist or touch long a cover of a song and press (red +) in the context menu:
Now, the song is marked:
To save this marked song within a new playlist press the My Records symbol upper left on the screen:
Now the left menu opens and choose “Save as”:
After naming the “new playlist” a new symbol and the name of the playlist will be shown in the headline: