He has no idea it is his birthday.

Let the children go in first." Maria now entered the study with Adrian and Bessie.

They carried bouquets in their hands, and the young wife had dressed the little girl so prettily that, in her white frock, she really looked like a dainty fairy.
Peter now knew the meaning of the singing, warmly embraced the three well-wishers, and when the madrigal began again, stood opposite to the performers to listen.

True, the execution was not nearly so good as at the rehearsal, for Maria sang in a low and somewhat muffled voice, while, spite of Wilhelm's vehement beating of time, the warmth and verve of the day before would not return.
"Admirable, admirable," cried Peter, when the singers ceased.

"Well planned and executed, a beautiful birthday surprise." Then he shook hands with each, saying a few cordial words and, as he grasped the Junker's right hand, remarked warmly: "You have dropped down on us from the skies during these bad days, just at the right time.