What is a homonym for rap?

There isn't a perfect homonym for "rap" in the sense of the musical genre. However, there are a few words that sound the same but have different meanings:

* Wrap: To enclose or cover something.

* Rap: To strike with a sharp blow, often with a stick or weapon (though this is much less common in modern usage).

So, while not a true homonym, "wrap" is the closest word that sounds the same as "rap" and is commonly used.