This lick is all about playing a melody alternating between an open string and fretted notes. The lick uses the A Harmonic minor scale, which is the same as the A minor scale, but with a sharp 7th degree. For example, A minor has the notes A B C D E F G (no sharps or flats) while A harmonic minor has the notes A B C D E F G# (the sharp 7th). Take it nice and slow at first if you're struggling to get the open string to ring cleanly between the fretted notes!