Tens of thousands of people are attending the Psy 'Happening' concert this evening in Seoul and the World Cup Stadium.

The show begins at 6:30pm local time and already the scene around the stadium is overflowing with people in white, the dress code for the highly anticipated event.

But who is in attendance?  

Well, aside from a wide array of celebrities, most notably Psy's fellow YG Entertainment label mates, there are Psy fans of all shapes and sizes.

Every age is represented in the crowd - old to young - grandparents with their grandchildren, whole families.  Students from middle and high schools, and those who are in university - businessmen, professionals - it seems that Psy and his music have reached a whole range of people.

And that extends far beyond the borders of Korea.  There is also a huge foreign presence at the Psy Happening Concert.  Media from around the world - high profile European media, and those from the states and all parts across Asia.

Fans too.  Seoul has a thriving expat community so that is not at all surprising, but there are people who have flown in just for the Psy's Happening Concert.  These fans have come from nearby Japan and Taiwan and as far away as South America to see the famous singer live in action.

Many high-profile Korean celebrities are expected to be in the audience and even some American celebrities.  Scooter Braun and his friend, American film director Jon M. Chu are there too.  The two have been posting Twitter and Instagram updates about their trip to Seoul for Psy's Happening concert for the past couple days.

At any rate, the fans, celebrities, and media filling the World Cup Stadium for the show is astronomical - and Psy's Happening concert is expected to be the must-see concert of the year.