Most music in general follows a rule of 4. 4 beats per measure, 4 measures before a tempo or beat change.
Think of it like this –
1 2 3 4 // 1 2 3 4 // 1 2 3 4 // 1 2 3 4 // 22 33 22 33 // 22 33 22 33…
EDM typically seems to follow this same rule but they do mix in the rule of 3.
Heavy metal follows the rule of 3.
Think of it like this –
1 2 3 // 1 2 3 // 1 2 3 // 111 222 333 // 1 2 3…
It is rare that other genres will mix in the rule of 3 seeing as it changes the entire structure of a song. EDM can do this because they mix so many different songs while they perform. In this way, EDM is unique. Because just as it is uncommon for other genres to follow the rule of 3, it is uncommon for hard rock to follow the rule of 4.