From Sew House Seven:
Traditionally a muumuu is a loose dress of Hawaiian origin that hangs from the shoulder and is unrestricted at the waist. The Montavilla Muumuu is a cheeky take on the Hawaiian classic - a modern version that is simply muumuu inspired and can be belted or cropped as mini dress or a top. Wear this dress beltless - muumuu style, or use the tie or an existing belt for more waist definition. The top is darling tucked into a skirt or pants or worn more casually untucked. Options & Features:
The details on this garment are simple yet unique. The outer leg of the shoulder dart gathers slightly to form a ruffle while an elastic tunnel gathers the sides at the underarm for an easy and comfortable fit with no closures to sew.
When sewn in a more structured fabric, the sleeve/ruffle is more crisp and prominent. Sew it up in a fluid fabric such as rayon challis and the ruffle floats or flutters gently.
The top (version #1) is somewhat cropped and lands around the high hip. The mini dress (version #2) lands a little above the knees and the full muumuu dress (version #3) lands just above the ankles. Both long and short dresses feature oversized pockets and the full muumuu features long front slits/vents at the hem. The waist tie is optional.
This is an advanced/ beginner level pattern. Sizes 00 - 20