The Singing Summit is a place where you send your mermaids to sing and summon mermaids. First, your mermaids have to sing and then they have to arrive (same amount of time). You can also speed up time by spending pearls. There are two singing summits. The first one you get automatically when you download the app. For the second one, you have to get at least 15 unique mermaids and three, three star realms. But, you can also purchase it with 1500 pearls.