For Organ. Use at your own discretion! (Maybe a sneaky postlude following your rendition of BWV 620 - that is, if you're allowed a postlude during Lent.). JSB's Birthday is March 21. Formally titled Fantasia pro Organo Pleno super Fröhliche Geburtstag Herr Bach, John has given us the well-known tune rendered in Bach’s ‘big bad chorale’ style – full organ, stile antico with the cantus in the pedal. Have fun!