 Complete the following phrase:  In Mexico, rock music was tied into the youth revolt of the 1960s. Mexico City, as well as northern cities such as Monterrey, Nuevo Laredo, Ciudad Juárez, and Tijuana, were exposed to US music. Many Mexican rock stars became involved in the counterculture. The three-day Festival Rock y Ruedas de Avándaro, held in 1971, was organized in the valley of Avándaro near the city of Toluca, a town neighboring Mexico City, and became known as The Mexican Woodstock. Nudity, drug use, and the presence of the US flag scandalized conservative Mexican society to such an extent that the government clamped down on rock and roll performances for the rest of the decade. The festival, marketed as proof of Mexicos modernization, was never expected to attract the masses it did, and the government had to evacuate stranded attendees en masse at the end. This occurred during the era of President Luis Echeverría, an extremely repressive era in Mexican history. Anything that could be connected to the counterculture or student protests was prohibited from being broadcast on public airwaves, with the government fearing a repeat of the 