Simplify the following text for a Grade 8 native English-speaking person.
Original: The Canonic Variations on `` Vom Himmel hoch da komm ' ich her '' ( From Heaven above to Earth I come ) , BWV 769 , are a set of five variations in canon for organ with two manuals and pedals by Johann Sebastian Bach on the Christmas hymn by Martin Luther of the same name .
Simplified: The Canonic Variations on `` Vom Himmel hoch da komm ' ich her '' ( From Heaven above to Earth I come ) , BWV 769 is a well-known piece of music for organ by Johann Sebastian Bach . An organ with two manuals ( keyboards ) and pedals is needed to play this work .