How is the ula performed at Samoan weddings and family gatherings?

In Samoa, the ula is a traditional form of entertainment frequently enjoyed at weddings and other family gatherings. It is performed by two groups who alternate between singing and dancing.1

It is important to clarify that the ula described in the context of Samoan cultural life is a performance art, distinct from the Hawaiian term ulaula, which refers to a type of snapper fish.21