Why do all American V8 engines sound the same?

All American sports cars from the old muscle cars until now with V8 engines sound the basically the same. Like the Corvette, Mustang, GTO, etc. Even the Dodge Viper which has a V10 sort of sounds like an American V8. What's up with this? Do we have a lack of creativity or something? Why can't they or don't they sound like a European V8? They sound distinctly different. A V8 Vantage, R8, F430, and SLR all have V8's but they sure sound different from each other. Why is that?