Negativland is certainly audio-focused, but it isn't really music. It's been described as "audio collage", a vast salmagundi of clips, musical samples, and random noises.
I started listening to them in my college years (having found about them from Ivan Stang's book High Weirdness by Mail), when, frankly, I was more interested in weirdness for weirdness's sake than I am now. I was going to the show as much out of nostalgia as for current active interest.
It was a pretty good show. It wasn't very audience-engaged, because it was mostly the three performers at their stations doing their things. (In fact, they gave out blindfolds to let people tune out the visuals, since "what we're doing is essentially radio.")
I found it fascinating to watch them working, though; they were doing a fascinating piece of media-juggling. One guy was juggling a stack of tape cartridges (not normal cassettes; I don't know much about that technology), one guy was juggling LPs and CDs among two turntables and an unknown number of CD players, and one guy was juggling cables manipulating sound effect boxes. (Their work was analog, not digital--the CD players might have been digital, but their interaction was analog.)
I would watch them again, though I didn't find myself reaching for the wallet to buy CDs.