When it comes to describing music or singing, the term "melodious" is often used to indicate harmony and pleasing tones. To convey the idea of "more melodious," one can employ synonyms such as tuneful, mellifluous, sonorous, or harmonious. These words suggest a pleasant musical quality that is soothing to the ear. Additionally, one could use terms like euphonious, musical, pleasant, or sweet to describe music that is more melodious. All these words add a layer of nuance to one's description of music or singing, and can be utilized to enhance the vividness and impact of one's writing.