I had an excellent time at the concert. There were 14 guys on stage from all over the US, plus the UK, Denmark, and Finland. The process is that they come together at the start of the week, spend a day getting their sound in order, then present musical ideas to the group. Those that get a good response are fleshed out into arrangements for the whole ensemble, which they then spend the rest of the week rehearsing. And then, the concert. There were a lot of keyboards, but also guitars, electronic wind instruments, and at least one drummer.
The concert had between an hour and an hour and a half of the material they rehearsed. The pieces spanned a range of styles, from non-rhythmic soundscapes to stuff like jazz combo improv, but with all electronic instruments. One really interesting piece was performed by about five guys using iPhones or iPads and an app called Morphwiz, which played tones that varied continuously in frequency and timbre based on how fingers were moved on the touchpad.
Apparently, they usually follow the rehearsed pieces with about an hour of jamming, but as the rehearsed section was ending, lightning started flashing in the distance, and about five minutes into the second part, a heavy rainstorm started. So, the concert was cut short as the musicians powered everything down and covered it with tarps.
Most of the audience that wasn't residents bailed out at that point, but I stuck around hoping to buy some CDs, and also because I didn't want to start the hour-long drive back to Phoenix during a thunderstorm. I ended up spending a bit of time talking to the musicians backstage, who, when I told them I'd flown in from LA for the concert, asked "are you crazy?", "how did you find out about this?", and "did you enjoy the show?" When I told them that I loved everything Tangerine Dream did in the '70s, they started saying "well, you might like this CD of mine..." I wound up buying $75 worth of music (aka all the cash I had on hand).
All in all, a great experience.