Understanding Vocabulary in Context: Vicissitudes

In the context of the following passage about the impact of art on society:

'Art has always held a mirror to society, reflecting both its vicissitudes and triumphs. The paintings of the Renaissance captured the tumultuous change of that era, while contemporary installations often invoke a sense of urgency about current sociopolitical crises. Understanding art requires us to delve beyond surface aesthetics, examining the underlying themes and contexts that shape each piece. As we unravel these layers, we discover how art not only informs our understanding of history but also provokes necessary dialogue about our present.'

What does the word 'vicissitudes' most closely mean in this context?