Watch the teaser for SNSD TaeYeon's 'All with You' the OST of 'Moon Lovers: Scarlet Heart Ryeo'

Following the sneak preview, the official teaser for SNSD TaeYeon's 'Moon Lovers: Scarlet Heart Ryeo' OST is now out!

The title of her new song is 'All with You' and it will be released on September 13~