Which composer is noted for bridging the Renaissance and Baroque eras?

The composer noted for bridging the Renaissance and Baroque eras is Monteverdi. His work played a significant role in the transition between these two musical periods. Monteverdi is best known for his innovations in the use of harmony and expressive melody, which were fundamental in the development of early opera and a more modern approach to music composition.

His seminal work, "L'Orfeo," is widely recognized as one of the first operas and represents a crucial step in the evolution of music from the complex counterpoint typical of the Renaissance to the clearer, more emotive textures and forms of the Baroque period. Monteverdi's ability to blend Renaissance techniques with new Baroque ideas, such as the use of continuo and the focus on dramatic expression, illustrates his pivotal role in this musical transition.

In contrast, the other composers listed, while influential in their own right, did not fulfill the same bridging role. Vivaldi was firmly rooted in the Baroque period, Palestrina was a key figure in the late Renaissance, and Bach, although he incorporated various styles, is primarily a towering figure in the Baroque era itself rather than a transitional figure.