Bathroom singing is a popular phenomenon
Is it healthy?
Yes it is. Many people find it pleasing
What are the best songs to sing in the bathroom?
on YouTube, and was the most viewed video on YouTube from November 24, 2012, when it surpassed the music video for "Baby" by Justin Bieber featuring Ludacris, to July 10, 2017, when it was surpassed by the music video for "See You Again" by Wiz Khalifa featuring Charlie Puth.
The phrase "Gangnam Style" is a Korean neologism that refers to a lifestyle associated with the Gangnam District of Seoul. The song and its music video went viral in August 2012 and have influenced popular culture
Bathroom singing
Bathroom singing, also known as singing in the bathroom, singing in the bath, or singing in the shower, is a widespread phenomenon. 
Many people sing in the bathroom because the hard wall surfaces, often tiles or wooden panels, and lack of soft furnishings, create an aurally pleasing acoustic environment. The multiple reflections from walls enrich the sound of one's voice. Small dimensions and hard surfaces of a typical bathroom produce various kinds of standing waves, reverberation and echoes, giving the voice "fullness