The phrase "song of worship" can be replaced with several synonyms, each with its own unique meaning and connotation. "Hymn" is a commonly used synonym and typically refers to a religious song sung specifically in a church setting. "Anthem" is another synonym that implies a powerful, uplifting message and may be associated with national or religious pride. "Chant" suggests a repeated and rhythmic tune that is often used in meditation or spiritual practices. "Praise song" is a more modern synonym that emphasizes the act of praising and showing gratitude to a higher power. Ultimately, the choice of synonym depends on the context and desired tone of the music.