This chapter analyzes the impact on the population of the expansion of nightlife in Madrid from the 1880s on. More particularly, it studies public fears raised by alcoholism and flamenco that led to this music being identified with social disorder and immorality. The Fuencarral Street murder (1888), in which a flamenco aficionado was involved, shocked the public and triggered a campaign against flamenco and the culture associated with it, known as flamenquismo. Behind this campaign, however, was fear and hatred of rural immigrants from Andalusia, who transformed Madrid’s culture and elicited the opposition of the population most affected by the rise of hunger and deprivation in Madrid. At the turn of the twentieth century, this situation led to flamenquismo being used as a catchword to designate any social problems affecting Spain in the wake of the 1898 desastre.