This lesson comes from my Method Book Volume 2.
Below is the lesson for A Minor (Page 11) including the scales and chord progressions. The lesson for the Romance by Kuffner (Page 12) starts 4:45 mins. The lesson for Leccion by Sagreras on (Page 13) starts at 6:25. Be sure to watch the whole video straight through to get an overview and to not miss any info.
Below is a recording of the duet with my friend Natasha Pashchenko as well as the chord song Star of County Down (Page 14). Please note that the updated version of my book does not use slurs for the duet. If you are playing the duet without a teacher just play the melody on its own.