In this YouTube video, which is his personal channel, Groban sings a “very much requested song” which he dedicates to all the:
“… brave front line workers around the country but especially those in the epicenter at New York Presbyterian Hospital and Columbia University Irving Medical Center and around NYC.”
The song is the well known “Hallelujah“. It was produced by Leonard Cohen, released in 1984. Though that time was no such a big success, it gained fame later with the movie Shrek which was aired in 2001.
It took a lot of time for this song to catch up,but since than many famous and not so famous artists sang it.