Symphonia is a beautiful word that typically refers to a musical instrument or a harmonious sound. When it comes to finding synonyms for this word, there are several choices available. One option is the word "harmony," which suggests a pleasant and synchronized mixture of sounds. Another word that works well is "orchestration," which implies a sophisticated and carefully coordinated arrangement of musical parts. "Melody" is yet another option, denoting a pleasing tune or sequence of musical notes. Other words that might fit the bill include "rhythm," "composition," and "ensemble." Whatever word you choose, it should convey a sense of cohesive beauty and musical artistry.