The phrase "beating drum" is often used to describe a steady and rhythmic sound, but there are many synonyms that can be used to add variety to your writing. "Pounding drum" suggests a louder and more forceful sound, while "thumping drum" implies a heavier and more impactful beat. "Thudding drum" connotes a duller and slower rhythm. "Rattling drum" suggests a more chaotic and erratic sound, while "echoing drum" implies resonance and amplification. "Drumming beat" is a more general and versatile alternative, and "percussion" can be used to refer to any instrument that produces a consistent rhythm. By using these synonyms, you can add color and texture to your writing while still conveying the steady beat of a drum.