ordopraedicatorum: A plenary indulgence may be gained on Pentecost Sunday if the hymn Veni Creator S
ordopraedicatorum: A plenary indulgence may be gained on Pentecost Sunday if the hymn Veni Creator Spiritus is sung or recited and all the usual conditions are met. The usual conditions include confession within seven days of the event, communion on the day, and detachment from sin. -- source link