Cuban singer Santiago Feliu, dubbed "a hippie of communism," died early Wednesday in Havana, official media said. he was 51.

"He had a heart attack," wrote singer-songwriter Silvio Rordiguez in his blog Segunda Cita in a post devoted to Feliu and entitled "Santy," as he was known to his friends.

Radio Rebelde noted that the musician had been scheduled to give a concert on Saturday in Havana at the Fabrica de Arte Cubano.

Feliu, a Havana native, was one of the most popular Cuban singers in Latin America and had accompanied performers such as Rodriguez, Joan Manuel Serrat, Luis Eduardo Aute, Fito Paez and Pablo Milanes on tour.

The creator of songs such as "Ansias del alba," "Para Barbara" and "Sin Julieta," Feliu is part of the second generation of the Nueva Trova Cubana along with other figures such as Carlos Varela, Gerardo Alfonso and Frank Delgado.

He recorded 11 albums, the last one entitled "Ay la vida," which was released in 2010.

Described by biographer Juan Pin Vilar as "a hippie of communism," Feliu was always seen as a rebel and a utopian.

At the same time, he always showed interest and commitment to social movements, ranging from the Cuban Revolution, about which he was critical as well as full of praise, to Mexico's Zapatista movement and the now-defunct Colombian rebel group M19.

Feliu lived abroad for extended stretches and called Argentina his "second home."

At the Casa de las Americas in Havana in 2012 he celebrated his 50th birthday with a concert that was heavily attended by fans of all ages. EFE