Once, at Rabbi Yosef Yitzchak of Lubavitch’s festive meal for the day of Simchat Torah, the chassidim danced and sang for a long time. When the dancing ended the Rebbe commented:

“The Alter Rebbe says in the Tanya in the name of his teachers, that if an angel were present at an assembly of ten Jews, even if they did not speak words of Torah, fear and dread would overcome him and his existence would be nullified completely. If so, just consider: from the dancing of such a large group of Jews, and not to mention the good intentions that each one had while dancing, what jealousy would the angels have!

And the Rebbe instructed that the dancing and the singing should continue.

(Sefer Hasichot 5705, p. 59)