Wiktionary
n. One who does great deeds but receives little or no recognition for them.
Wikipedia
Unsung Hero, also known as Uhero Magazine, was a music magazine publication based out of Gettysburg, Pennsylvania. It was an American magazine devoted to unsigned music and popular culture, centralized in the mid-Atlantic region of the United States.
The magazine focused on unsigned music artists and bands to spotlight, as well as other music-related articles.
Usage examples of "unsung hero".
First you were an unsung hero, then you lost your innocence, then your wings - until a beautiful and intelligent girl came along and pulled you out of the nose-dive.
He would later become a Jedi Master and an unsung hero of the Clone Wars.
I believe I had rather be Firaqa's great unsung hero than the target of ten or twenty angry mages!
He is the unsung hero who solves riddles of the ages, while the Reconnaissance and Retrieval teams swan about aboveground taking all the glory.