Massó was a member of Menudo during their most commercially successful period in the States, which included the group's highest-charting U.S. single, "Hold Me" (#62 on the Billboard Hot 100.)
In 1985 Menudo visited Manila, Philippines twice for their concert at the Folk Arts Theater, with several guest appearances on Eat Bulaga, Vilma in Person & GMA Supershow.
In 1986, Charlie sang " Di Na Natuto", a Tagalog song to serenade a young Filipina originally sung by Gary Valenciano.
In 2001 he appeared in 12 Horas, a Puerto Rican movie written and directed by Raúl Marchand Sánchez.
Massó quit El Reencuentro during 2015 and joined Farrait, Cancel and Reyes in another Menudo-reunion band they named "Menudomania Forever".