As DJ Tropesphere points out in his recent post, tropes were a way to re-immerse monks in the liturgy. But the most fascinating thing about tropes to me is how the trope texts allow us to keep our finger on the pulse of intellectual activity at the time. Far from being empty vessels, transferring original truths back into the mouths of monks unchanged, Clunaic reforms, and tropes with them, shaped—and were shaped by—contemporaneous theological developments. Like the text glossing of a manuscript, in which commentary filled the margins surrounding the original text, tropes form a musical frame around pre-existing chant. As such, paying attention to what topics the tropes emphasized (Marian imagery, Christology) can tell us what the authors considered to be important. Riffing off of Zach’s recent post, troping a Kyrie is like taking a pop ballad and remixing it as a dance track. Both tell us something about the participants’ changing values.
When telling the story of music history, tropes are usually big news because they were new, and we like to track what we think of as the forward edge of history. (We deal with the origin of a genre, then follow its development only as long as it does so dynamically. To my knowledge, no one has ever written a chapter called “Gregorian Chant in the Seventeenth Century,” though I would love to be proven wrong!) But as Taruskin’s discussion implies, tropes are important for far more than just being new. As additions to a pre-existing set of texts, they show us how a new generation of believers made the liturgy their own.