If historical significance alone were enough to rank local concerts, Kraftwerk's September visit to The Bomb Factory would easily be No. 1. The German quartet may not be a household name, but with songs like "Autobahn," "Trans-Europe Express" and "Tour de France," they've have had an impossibly huge influence on the past four decades of music, from rock 'n' roll to hip-hop to electronic dance music. They may or may not have ever even played here before this year: Bootlegs exist of a show supposedly recorded in Dallas in 1975, but there are strong indications that it was recorded elsewhere and little outside evidence to suggest the show even happened. But none of that is necessary to understand why Kraftwerk's stop in Deep Ellum was so remarkable. It was a show that played by an entirely different set of rules from other concerts, from the breathtaking use of 3-D imagery to the ingenious deployment of robots that took the place of the band members at one point. Kraftwerk's music still feels ahead of its time, but even as they revisited their past work they pushed it into the future, redefining what the concert format itself is capable of.