To add a video for Jacques-François Gallay / Fantaisie, on a cavatina from Belisario by Donizetti, Op. 42, just enter the video‘s YouTube link:
example) https://www.youtube.com/watch?v=XXXXXXXXXXX
Search YouTube for Jacques-François Gallay / Fantaisie, on a cavatina from Belisario by Donizetti, Op. 42