Adagio from flute concerto in G - Pergolesi

The soloist - orchestral relationship in this piece is pretty typical - the soloist is clearly the star and the orchestra has a very basic part when solo sections are being highlighted. Otherwise, the orchestra is playing melodies and has a much more full, complete, balanced sound. The piece doesnt have a catchy melody, but instead focuses on a pattern of 2 sixteenth notes followed by an eighth. Whenever this rhythm returns, I feel like I have returned to the main motive - it ties the piece together and makes it more unified. The flute part itself is mostly in the lower to middle octaves and doesn't venture very high in general. The piece begins in minor, but modulates to the parallel major a few lines after the flute initially entered and remains in major until the end, where it returns back to the minor key. This affected the entire mood of the piece in an interesting way because I wasn't sure if I was supposed to be feeling happy or sad.