Not every song goes viral, and the ones that do share structural traits. The most important is the hook window — a catchy, emotionally distinct phrase or melody that lands within the first 5 to 10 seconds. Streaming platforms count a play after 30 seconds, but TikTok clips are even shorter. If the hook does not grab immediately, the thumb scrolls past.

Repetition is the other key ingredient. Viral songs tend to have simple, looping melodic phrases that burrow into memory after just one or two listens — what psychologists call an earworm.