This type of instrumental and keyboard composition featured layers of melody, where the same tune "chased" itself throughout the piece. the more layers, the more complex. j. s. bach once improvised one of these on the spot that had 6 "voices" or layers to it. what is this type of piece called?

The caves at lascaux were closed in 1963 because a. vandals were destroying the paintings b. the collective breath of the many visitors caused the paintings to corrode c. the weather was destroying the paintings d. the government of france wanted scholars to be able to study the work without distraction