The triumphant return to Rome of Måneskin — arguably the only rock stars of their generation, and almost certainly the biggest Italian rock band of all time — coincided with a heat wave across Southern Europe. On a Thursday morning in July, the band’s vast management team was officially concerned that the night’s sold-out performance at the Stadio Olimpico would be delayed. When Måneskin finally took the stage around 9:30 p.m., it was still well into the 90s — which was too bad, because there would be pyro. The need to feel the rock may explain the documented problem of fans’ taste becoming frozen in whatever era was happening when they were between the ages of 15 and 25. Anyone who adolesced after Spotify, however, did not grow up with rock as an organically developing form and is likely to have experienced the whole catalog simultaneously, listening to Led Zeppelin at the same time they listened to Pixies and Franz Ferdinand — i.e. as a genre rather than as particular artists, the way the writer Dan Brook’s generation experienced jazz. The members of Måneskin belong to this post-Spotify cohort. As the youngest and most prominent custodians of the rock tradition, their job is to sell new, guitar-driven songs of 100 to 150 beats per minute to a larger and larger audience, many of whom are young people who primarily think of such music as a historical artifact. Starting in September, Måneskin brought this business to the United States — a market where they are considerably less known — on a multivenue tour, with their first stop at Madison Square Garden.