Harmony supports the structural design of musical components by helping to define climatic and cadential points in each phrase. In such songs the harmony may vary in each stanza. However, composers are usually sensitive to how the harmonic accompaniment mirrors the organizational structure of the text. Harmony heightens the meaning of text. Certain words are more emotionally charged than others in both prose and poetry.
Dynamic levels are a natural indicator for emotional mood.
Loud dynamics are associated with vigor, turmoil, conflict, valor, et al. Marches, fanfares, and triumphal music tend to be loud. Soft dynamics are associated with tranquillity, repose, calmness, sensuality, et al. Love songs, lullabies, wistful and melancholy songs and certain sacred music tend to be soft. The wrong dynamic level has the effect of making a piece of music ineffective and illogical as an indicator of mood.