Just found this on the Trinity website! It's one of two videos from a concert performed in February of this year.
Here's the blurb on this concert:
The Trinity Choir, along with Guest Conductor George Steel, General Manager and Artistic Director of New York City Opera, perform Music from the Sarum Rite. These gorgeous compositions – taken from the elaborate and theatrical liturgy of pre-Reformation England – feature soaring soprano lines and rich choral textures by masters such as Robert Wylkinson, William Byrd, Thomas Tallis, and John Sheppard. Although rarely performed today, the Sarum Rite includes some of the most exquisite music of any age. Purchase tickets online here. Tickets can also be purchased at the Trinity Gift Shop, inside Trinity Church. Watch a video of George Steel on the "music that speaks to us with an emotional clarity you wouldn't expect from...such a far away time.
Here's a PDF of the program. And below is the video of the George Steel discussion.