I would like to ask for help with proper understanding of the following paragraph (included to give some context):
As I thus mused there fell upon my ears the sounds of sonorous chanting that swelled symphonically from somewhere far below. Its measured cadence rose and fell solemnly as if it were borne from a distance incredible to human ears.
I find it very hard to infer the correct meaning here, mainly because "cadence" has various meanings and being a non-native speaker, this is particularly difficult for me. My best guess is that the chanting was somehow organized and the tune (intonation?) was going up and down (high and low), maintaining somehow a solemn nature?