To add a video for Georges I. Gurdjieff/Thomas de Hartmann / Chant du Mercredi Saint (Hymn for Easter Wednesday), for piano, just enter the video‘s YouTube link:
example) https://www.youtube.com/watch?v=XXXXXXXXXXX
Search YouTube for Georges I. Gurdjieff/Thomas de Hartmann / Chant du Mercredi Saint (Hymn for Easter Wednesday), for piano