X-Alfonso (born c. 1974 as Equis Alfonso) is a Cuban hip hop and afro-rock musician, who played with Audioslave in a concert in Havana on May 7, 2005 in "Tribuna Anti-imperialista".

From early 1990s, when he graduated, he joined the Cuban group Síntesis led by his parents Carlos Alfonso and Ele Valdès, as singer and composer or co-composer.

That’s how I learned to play the instruments, through necessity.” The group started as a vocal quartet, then turned to symphonic rock before going on to explore a fusion between Afro-Cuban music—Cuban roots—and contemporary music.

In 2008-2009 he directed the documentary Sin título, about the daily universe of Cuban artists and conceived the Cuban Art Factory (FAC, in Spanish), which as of 2010 becomes a brand new space with transmedia vocation and where emerging young artists (musicians, filmmakers, painters, dancers) converge with others with a longer career.

Since 2015, and with X Alfonso in front, FAC has become one of the most important cultural projects in the country, with an artistic proposal, an environment and an audience that have made it worthy of being considered one of the one hundred best places in the world, according to TIME magazine.