Flor Peeters was organist of the St Rombaut Cathedral, Mechelen, Belgium, and a renowned teacher and performer. "Aria" is his best known organ piece with its plaintive melody set against pulsing chords.
A native of Belgium, Peeters studied at the Lemmens Institute and returned to teach there. He was a renowned organist and composer with a distinctive style. Melody is one of his "Sixty Short Pieces" and lasts all of 30 seconds. In those seconds you can hear the angels sing.
He wrote this piece on this hymn tune with the melody in the tenor (played on a reed stop).