With his hand on his chest, he blew a kiss of gratitude for the enthusiasm with which the Estadi Olímpic Lluís Companys enjoyed the hour and three-quarters of the concert. This was the gesture of Dan Reynolds, the singer, leader and spokesperson for Imagine Dragons, when the concert ended. Believer, the finale of a performance filled with confetti, sing-along rock, and an almost excellent sound. Quantitatively, the Las Vegas group is the biggest rock band to emerge in the last 15 years. On Spotify alone, songs like Demons, Thunder and Believer They have more than 2.7 billion views, more or less like Long live life by Coldplay. What's the secret?