Mexico City, Mexico – The seven-year project to restore the organs at Mexico City’s Metropolitan Cathedral has been completed, the National Culture and Arts Council, or Conaculta said.

The Evangelio and Epistola organs will be able to produce "more than 400 vibrations per second," Conaculta said in a statement.

The organs were damaged by a fire in 1967 and required a painstaking restoration process.

"They are both jewels with an intricate system," organ expert Gerhard Grenzing said, adding that restoring two monumental organs was "a science" because the instruments had "their own needs to protect their structure."

"I believe there are no other instruments on the entire continent as beautiful as these twin organs in Mexico City that reflect the Iberian style of the great masters of the craft," Grenzing said.

The Epistola organ’s bellows "breathe like human lungs would" and "carry the wind to the pipes, which must be in harmony, seeking the best sound path for the dissemination of the music at a venue like the cathedral," Grenzing said.

Obtaining historical information was the biggest challenge because from both a musical and a technical standpoint "you have to fill in the blanks about the processes used to build the instruments, the wood, the original skins used that have a life of 200 years, as well as the lead used in the pipes," the expert said.

"Pieces with so much history, with so many pipes, and so much complexity, always open up the unknown, so the research work is something that should always be done as you go along," Grenzing said.

Spanish organist Andres Cea said the Mexico City cathedral project was one of the most important in his career.

"These two instruments are without a doubt the most beautiful and important in Ibero-America, and having the opportunity to bring them to life via the music is a historic event for any musician," Cea said.

The organs were played at a concert last week, the first of a series of musical events to celebrate the instruments’ restoration, the Mexican press reported.

This was the first time that the public heard the two organs played simultaneously in centuries, the Rev. Felipe Galicia said.