When Pope Francis visits the southern Mexico state of Chiapas in February, the Diaz sisters will serenade him with music from the region's favorite instrument: the marimba.

The wood-planked instrument resembles its metal cousin, the xylophone. And nobody knows marimbas better than the four Diaz sisters, who began playing them in churches three decades ago at the invitation of the late Chiapas Bishop Samuel Ruiz.

Ruiz tried to get more of Chiapas' heavily indigenous culture into the local churches.

While the marimbas' light, cheerful rhythms are more associated with seafood restaurants and sunny town squares, the Diaz sisters ring a broad range of moods out of them.

The sisters have now been joined in the band by some brothers and other relatives. And they are ready for the pope, who will visit the Chiapas' colonial city of San Cristobal de Las Casas on Feb. 15.

"It is an honor for us to be up front. It is a gift from God," Marta Diaz said.

Textile worker Guadalupe Lopez Hernandez also has a very local surprise she's preparing for Pope Francis.

Lopez Hernandez is embroidering a miter that the pontiff will wear during his visit to San Cristobal.

"I'm very happy, very excited," she said, adding "I'm happy because I love my church a lot."