How would you anaylsis this passage?

The image is from prelude of Wagner's Opera: "Tristian and Isonde"

Well, what do you want to know?

EDIT: I'll tell you what I find interesting about it. There are two fascinating ambiguities going on here:

1) There is a conspicuous lack of consonances on strong beats. The points of greatest rhythmic weight are also the points of greatest harmonic and melodic instability. In the cello melody: Leaps of sixths in an empty harmonic environment - intervals that tend to lead elsewhere, and indeed do. Where do they lead? To half-diminished seventh chords, which themselves are chords that tend to lead to other chords. Where do the half-diminished seventh chords lead? To a dominant seventh chord with a #11 suspension. The closest thing to a real resolution is in bar 17, a deceptive cadence, but even that is undermined by a sharp #11 appoggiatura.

2) The first half of this beginning can be described as roughly consisting of pairs of events. Because the pairs are identical, the first event is automatically perceived as stronger. Even so, the "weak" events are located in a higher frequency spectrum than the "strong" events, which means that they have a psychological accent due to heightened tension, and therefore the relative strength of events within a pair becomes more ambiguous. The start of the second pair contains a longer head (cello melody), which creates even more tension before the "Tristan chord", which it turns out doesn't really appear because the voicing of the half-diminished seventh chord has changed. This is just enough change to keep the listener on their toes and guessing at what comes next. Because the chord resolves using the same type of voice leading, although not the same type of harmonic movement, it seems for a second that the music hasn't really changed. That's why he now does away with the solo cello melody and goes straight to the half-diminished chord - which makes its effect even weaker than it would have been. To counteract this relative weakness, the material now moves a whole octave up in frequency. The interesting thing is that, even though the change in frequency spectrum is dramatic, the interval of transposition is an octave, which is a very stable interval, which means that it is not overly strong. Basically what Wagner did was distribute the weight of psychological emphasis onto two parameters, rhythm and frequency, instead of only frequency. The net result is arguably the same but it has a very nuanced effect in the mind! He weakens the second half of this event further by removing all explicit harmonic information and leaving only octaves (note that the weak part is still in a higher register).

The structural scheme of the prelude is a little bit complicated. I would say the phrase grouping for this passage would be 4+4+4+2+1+1 (assuming an empty first bar instead of an anacrusis). It should be clear that he increases the macro rhythm for added tension, but I would need to spend a little more time with the music to be able to draw any useful insights from the overall structure of the end of this passage in the context of what comes after it. Anyway, this is what I could glean.