Unison choir (or solo voice) and organ. Text is the BCP Collect for the Day of Pentecost. Slow and prayerful: short enough for an introit, long enough for a short anthem.
O God, who on this day taught the hearts of your faithful people by sending to them the light of your Holy Spirit:
Grant us by the same Spirit to have a right judgement in all things,
and evermore to rejoice in his holy comfort, through Jesus Christ our Lord: Amen.