Which of the following is NOT representative of music of the medieval period?

In the context of the medieval period, the statement that harmonies were influenced by non-European music for the first time is not accurate. During this time, Western music was primarily developing its own distinct styles and characteristics, and the major influences were predominantly internal, stemming from earlier European traditions like Gregorian chant and the art music of the church. While there were some interactions through trade and conquest that could introduce elements from non-European cultures, these influences on harmony were not as significant or recognizably impactful during the medieval period as they would become in later eras.

In contrast, the centrality of the Mass as a musical genre encapsulates the vital role of religious rituals in medieval life and music, making it a defining characteristic of the period. The emergence of secular themes reflects the gradual shift in focus toward human experiences outside purely religious contexts, which became more prominent towards the late medieval period. Additionally, the prevalence of monophonic texture was indeed a hallmark of medieval music, as early composers primarily utilized single melodic lines before the development of polyphony later on.