The catacombs of Paris are explored with a lamp. Cum mortuis in lingua mortua (= With the dead in a dead language). The dead, the skeletons are addressed with the lingua mortua.

Pictures at an exhibition by Modest Moessorgski
It is a ten-part suite by Modest Musorgsky (1874) a Russian composer. Inspired by paintings by his friend the painter Viktor Hartman. I painted my version. These were projected through a keynote presentation by Jan Penninkhof while the suite was played by colleague Gerard van der Laan (pianist).
See this link:
https://www.youtube.com/watch?v=zEwUvacXPlY&t=223s