Was Jesus born in a stable? Whilst the angels sang? And an ox and a donkey piously brayed?

Merry Christmas

Angels don't sing. Not in Scriptures. There's no mentioning of an ox or a donkey in either account (Matthew and Luke). We don't know how many magi showed up (could have been any amount from two to a few thousand. Western tradition holds to three, eastern tradition maintains twelve; both guesses are utterly unfounded). The shepherds and the magi never meet, and are not even in the same account together.

Jesus was not born in a stable in a field, but in a house in Bethlehem. Luke tells us how the shepherds went from the field into the town of Bethlehem. In Matthew 2:11 the magi enter 'the house' and find Christ and Mary.

Right after the Exodus the Passover is instated (Exodus 12). The Israelites were to keep a lamb in their house from the tenth until the fourteenth of the first month. Hence pretty much every house contained a manger (like in our time pretty much every house contains a string of Christmas lights, most of the time in a box in the attic). That Jesus was put in the Passover-manger is of such enormous Theological significance that it's almost a miracle that popular tradition hasn't noticed it.