I love singing in the shower while my smartphone is playing a favorite song.
Ditto!   Though I just usually sing whatever comes to mind.   No smartphone needed. 
I like to play the song without lyrics and sing the vocals part. It's nice because the acoustics and reverberations make it sound like I am a better singer than I am in reality.
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
Exiles, "I needed a punk vocalist for the chorus and I was missing a punk vocalist to go with my vocals for the chorus. I knew Igor had a great punk voice so I called him because I knew it would be cool to sing with my son on the song."
Lyrics and composition.
Max said this: "The song is about the absurdity of the human condition in territories plagued by bloodshed all over the world. Not just recent events like Iraq, but also historical conflicts such as