The key of the song is F# minor and and the measure shown starts with a non-chord tone. this is because the chord used is a B minor in second inversion and the C# in the melody is a a neighbouring tone. it was prepared by a B and resolves to a B.
What I'm having trouble with is that the B chord continues and the melody Leaps down to a G# and then leaps back up/resolves to a B. I don't know of any non-chord tone that is prepared and resolved using leaps.
So I was wondering if it still a non-chord tone and if so what kind, or is this perhaps a different chord?