What is "cimorelli"

Cimorelli is a singing group that was popularized on YouTube, were signed to Universal Music's Island label, and currently they are composing and writing songs on their own. Cimorelli is made up of six sisters, Christina, Katherine, Lisa, Amy, Lauren, and Dani. Their singing style is mostly using a cappella with occasional instruments. They started posting covers of songs on YouTube, before releasing original songs. , the group has released five Extended Plays, a mixtape called Hearts on Fire, and a full-length album entitled Up At Night.