Depeche Mode’s 101 is, at first glance, a curious thing: a live double-album by a synth band. A recording of its “Concert for the Masses,” 101 marks the moment when doomy, cultish, electronic Depeche Mode, despite low American album sales and a lack of critical acclaim, declared they had arrived and ascended to the rare air of stadium rock. On June 18, 1988, 65,000 screaming, singing Southern Californians flocked to Pasadena’s Rose Bowl to celebrate DM’s coronation.

The concert also revealed the power of Southern California radio station and event host KROQ, which had turned Los Angeles into DM’s American stronghold through years of fervent airplay. KROQ’s innovative format, which brought “new music” to its avid listeners, soon spread across the country, leading to the explosion of alternative rock in the 1990s.

Eight years after its founding in Basildon, Essex, Depeche Mode, rooted in 1970s Krautrock, combined old-fashioned touring, well-crafted songs, and the steadfast support of KROQ to dominate Southern California, the United States, and then the world, kicking open the doors for the likes of Nirvana in the process. 101 is the hidden-in-plain-sight hinge of modern music history.