UNEAC (National Union of Writers and Artists of Cuba) produces the biannual International Danzón Festival.  UNEAC is one the preeminent institutions in Cuba, organizing a range of cultural events and representing Cuban professional writers, visual artists, and musicians. Below is the official signed letter of invitation for Charanga Tropical to perform at the International Danzón Festival.  

For English translation of letter of invitation as PDF, click here. 
National Union of Writers and Artists of Cuba
Association of Musicians
 
 
The Havana, March 10, 2015
 
Sir Sage Lewis,
Charanga Tropical
United States of America
 
Dear Sir,
 
From the 24th to the 28th of June of this year will take place the IX International Festival Danzon Habana, organized by the Association of Musicians of the Union of Writers and Artists of Cuba (UNEAC), dedicated on this occasion to the theme, El bolero en el danzón.
 
During this grand event, important theatres and locations of the capital city of Havana will feature outstanding groups rendering homage to artists who have achieved so much in the style of danzón as well as the style of bolero.
 
For the organizing committee it is an honor to invite Charanga Tropical to participate in the activities of the festival.
 
For reasons of limited finances to cover the cost of travel of travel and accommodation, it is important that these expenses be covered by you.

Hoping to receive confirmation before the 30th of April in order to include you in the corresponding program, we reiterate the pleasure that we would have to count on the presence of your prestigious group during those days [of the festival].
 
Receive our most cordial salutations,
 
Best Regards,
 
José Loyola Fernandez                                                                                                      Guido López Gavilán
President                                                                                                                                             President
International Festival of Danzón Havana                                                                    Association of Musicians
                                                                                                                                                                UNEAC