Latency is the issue, not bandwidth, and the internet isn't fast enough for live instruments across it (unless the performers happen to be on the same local uplink). Even me pinging Google is 23 ms, where as most actual home users will be 50-200 ms from me.
Latency on a home fibre will be significantly lower than a 56k dial-up connection.
Somehow the artists could collaborate remotely using a shared MIDI clock. Admittedly it was techno which is both loopy and predictable, but still a cool achievement nonetheless.
I have home fiber. Again, I have 20 ms to Google. 40 ms (approximately what you'd expect from two not-physically-far-apart home fiber links) is already in the range that playing traditional instruments in sync is basically impossible. At a more typical 100 ms between nodes, that's a full 16th note of lag at common tempos. You can get up to 200+ ms between continents.
I know people that have also done it with techno, but they consider the lag as part of their unique sound. It's not something you can do with music in a general purpose sense.