Final answer:
Giovanni Pierluigi da Palestrina's main focus in his musical works was on liturgical forms such as masses and motets which were sacred compositions performed in churches. His works reflected the characteristics of Renaissance music and contributed to the development of polyphony and sacred music during that period.
Step-by-step explanation:
Giovanni Pierluigi da Palestrina, a prominent composer of the Renaissance period, focused on liturgical forms such as masses and motets. These were sacred musical compositions that were commonly performed in churches. Palestrina's works reflected the characteristics of Renaissance music, including a focus on modes, rich texture in multiple parts, and a blending of musical strands. His compositions played a significant role in the development of polyphony and the flourishing of sacred music during the Renaissance.