[Tax-chick]

The angels never sang at the birth of Jesus for example.

Now, we don't know that for certain. We only know that the Gospel does not specifically mention their singing. However, Luke says that the "multitude of the Heavenly Host" was "praising God ..." That could have been singing. (/hairsplitting textual analysis)

[Harmless Teddy Bear]

:ties hair back together:

Their praise was in their saying.