It does sound amazing for a live performance and first appearnace in the US. The set is arranged so that we can't see their amps and stuff. The other thing I notice is they start out simple with repetition and they harmonize their songs well. The reaction of the audience is something we do not see today. At least for me. I'm too old to be going to some new band I just heard about. ETA: The last artist I remember who provoked that kind of reaction was Michael Jackson. McCartney explains about their songs.