Selena Gomez's A Year Without  Rain' is an amazing single ! The Catherine Deane grey halter dress she wore for the video was absolutely stunning & can be worn at prom or any other suitable formal occasion ! This she paired with Laura Elizabeth 'Emily' earrings in gold & Sergio Rossi 'Talisman' sandals.
Here's how you can get the look :

Laura Elizabeth 'Emily' Earrings in Gold - $99

Catherine Deane Isabella Long Dress - $900