We all know that yawning is contagious. Have you realised that singing is also contagious? Yes it is! I have tested and tried.
What is meant by contagious
?
Easily diffused or spread as from one person to another. ex: a contagious grin, contagious disease etc;
How singing is contagious and helpful?
Try this. When you walk into office or home , keep huming a hit song. If there are people around, atleast one will catch up with you and starts to hum or sing that song. Change the song after a while and see. The same person will change the song and join you. This way, one can create a mood around him. That’s the reason when I step into office I make it a point that I hum any fast beat numbers and have people joining me in. That way, a peppy mood is created and the day goes on real smooth. So, I infer that singing or humming is contagious and sets the mood for the people around you. 
Is there any medical term for this? or Am I the first one to find it out? 
I am coining the word contagious concert. So, start staging your own contagious concerts.
P.S. :- While drafting this post, learnt from an old friend that when one hums the other sings and vice-versa. True! 