Great story.. I had something similar when my grand daughter was in 3rd grade...
The kids, with family members who were veterans, invited them to school with no appearant explaination... I thought I was going to one of the familar singing concerts they put on...
I was blow away to be invited to the stage where I was included with other vets being recognized by all of the students and teachers in the school...
Yes they did all sing to us... 'The National Anthem' and 'America the Beautiful'... What a lump I felt over that.. First time in my life and I'm sure others up on that stage, may have ever been recognized in public for serving in the Armed Forces..
Kids, and their wonderful un-expected actions do make you feel great. I'm happy that this young boy, who's life you obviously have an great impact on, has chosen to honor you in such a manner.