Manchester United boss Louis van Gaal stunned his players at their Christmas Party by getting on stage and banging out a couple of songs!

The People says during the first-team festivities at The Place Aparthotel in Manchester the 63-year-old Dutchman looked on with ­assistant boss Ryan Giggs and the rest of his staff while stars like Wayne Rooney took to the stage to sing.

But Van Gaal then shocked his players by getting on to the stage and taking the microphone ­himself to croon Frank Sinatra favourites.

A United source said: "The manager was really getting into his singing and was in no hurry to stop so he stayed up there for a couple of numbers.

"He comes across as a really tough manager who expects ­everyone to follow his orders in all football matters because he likes to be in total control of that part of his club - just like Ferguson. But Van Gaal has ­another side - and the players loved it. They appreciated that although he is the manager he is one of them too and is a stickler for maintaining the team spirit.

"He's gone out of his way to make sure the harmony in the dressing room is as good as it can be and the Christmas party was another clear sign that he's ­building something good with his ­players on and off the pitch.

"The players have strict rules to follow, especially at meal times and for team meetings where the boss doesn't tolerate anyone being late.

"But he likes to let his hair down when the occasion demands and he really entered into the spirit of the Christmas party."