Hi! Not sure what trouble you might be having.
It appears the bass is pedaling on an A. While in the second measure there is an G Major with melody followed by a G Minor Maj 7. The G Major with an A pedal will create the sound of an A9 chord - a dominant chord craving resolution. When the Bb and F# are added half way through the second measure, it is altering the dominant chord a bit by making an A b9,13. Harmonically this sets up a lot of tension that gets resolved in measure 3 with the D Major chord. Note the strong descending chromatic line of B to Bb to A within that chord progression. The 13 of the A b9,13 chord is F#, which harmonically carries over into the third of the D Major chord.
Not sure if I really helped or hindered, but that's what I see on a cursory scan of those three measures.
Cool stuff! Thanks for sharing!