Western classical music is categorized into distinct eras such as Medieval, Renaissance, Baroque, Classical, Romantic, Modernist, and Postmodernist, reflecting evolving styles and tastes. Terms like "Renaissance" and "Baroque" are borrowed from art history, and these divisions help music historians understand compositional trends over time. However, assigning exact start and end dates to these eras is challenging because styles often overlap, begin and end at different times regionally, and scholars frequently disagree. For instance, a "late Renaissance" piece might sound very similar to an "early Baroque" work. The 20th and 21st centuries are calendar periods, not musical eras themselves; they encompass Modernist music primarily from the 20th century, and Postmodernist music which extends into the current century.