Dédé was born in New Orleans, Louisiana, on November 20, 1827, the fourth generation of a free family of that city.

Dédé's teachers in his youth included violinists Constantin Debergue and Italian-born Ludovico Gabici, who was the director of the St. Charles Theater Orchestra.

Within a few years, he found employment at the Théâtre l'Alcazar, a popular concert café in the city.

[8] Samuel Snäer Jr. (1835–1900),[9] an African-American conductor and musician, conducted the first performance of Dédé's Quasimodo Symphony on May 10, 1865, in the New Orleans Theater to a large audience of prominent free people of color of New Orleans and Northern whites.

[citation needed] In announcing the concert, the New Orleans Tribune described Dédé as "our well-known fellow citizen" and reported that the work had been "enthusiastically received" in France.

[b] In the course of his visit, he was made an honorary member of the Société des Jeunes-Amis, a Black fraternal organization.

They had one son, Eugène Dédé [fr], who became a music hall conductor and composer of popular songs.

[19] Dédé's opera Morgiane had its concert premiere on the 7th of February 2025 at the University of Maryland Clarice Smith Performance Arts Center, 138 years after it was composed.