![Jake Gyllenhaal and Annaleigh Ashford's video duet will give you goosebumps](https://mondrian.mashable.com/lead-img-jake-gyllenhaal-annaleigh-ashford-singing-sondheim.jpg)
Harmonies don't come much more wonderfully chilling than this.
On Sunday, to celebrate American composer Stephen Sondheim's 90th birthday, a whole host of actors and broadway stars took part in a feature length show that was broadcast live on YouTube.
Jake Gyllenhaal and Annaleigh Ashford,...