Staying without music is different from staying without singing...A person may or may not go a day without singing, a person may or may not go a day without music...but a singer,(a devout singer), cannot but sing, make melodies, hum, make funny beats etc. He/she cannot go a day without music,and cannot go a day without singing.
Every singer has that one equipment that is cherished and will have most likely invested in it way more than any other thing. This prized possession can come in different styles but perform one function. This equipment isn't overlooked but loved by the singer, even he doesn't know how much he loves it until it gets missing...or gets bad...or partially functional.
No other tool than the highly esteemed
"EAR PIECE / EAR PHONE"....