Interesting thing about that chord is it is a F half-diminished seventh chord (spelled enharmonically), but then changes to a French augmented sixth chord when the G# (leading tone perhaps?) resolves up to A. That Fr+6 chord then resolves irregularly to the final chord in that first phrase (measure 3), which is an E dominant. Is it a half cadence in A? We don't know because he moves the same phrase up a whole step, creating a sequential pattern, which ends in a half cadence in C, and is reiterated again with a half cadence in E. All of those keys (A, C, and E) share a chromatic mediant relationship with one another as well. That is, their roots are a minor or major 3rd apart, are of the same quality, and share one common tone. Other cool things to note are the bass line in measures 2-3 echo the alto in the first full measure. The soprano line that starts at measure 2 is an exact mirror of the alto in measures 1-3 and the tenor line mirrors, in reverse, the first and last pitches of the soprano line. There's a lot going on in those first opening measures, haha. But basically what is happening is that the blurring of tonality through contrapuntal writing is giving rise to nontraditional chords structures that might otherwise occur as linear "accidents".
Edit: Bela Bartok's "Bluebeard Castle" is another opera worth checking out. Also, Shostokovich's "Lady Macbeth..." is really good. I wasn't too into them either until I asked myself, "Well, how many operas have I actually been to?".
