When we listen to a song, our attention is usually focused on the lead singer's voice. But behind that voice, there are other voices that support, enrich, and empower it: the backup singers. They are the unsung heroes of popular music history. They usually stand in the dimly lit background of the stage, their names written in small letters on album covers, or not written at all. But without their contribution, many of our favorite songs would not have the same impact.

Doing backup vocals is much more than just singing "oohs" and "aahs" behind the lead singer. It is the art of blending one's own voice in perfect harmony with the main vocal, creating instant harmony, and weaving the emotional texture of the song. A good backup singer intuitively knows how to elevate the lead vocal without overpowering it, when to step forward, and when to pull back.

This role requires incredible musical talent and flexibility. One day they might need to add a powerful roar to a rock song, and the next day, add a silky harmony to a soul ballad. They are the chameleons of voice and must have the ability to adapt to any style.

The 2013 Oscar-winning documentary "20 Feet from Stardom" shed light on the world of these unsung heroes, bringing their stories to millions. The documentary revealed both the incredible talents of legendary backup singers like Darlene Love, Merry Clayton, and Lisa Fischer, and the bittersweet reality of living on the edge of fame.

The stories of these artists often contain a paradox. While they have the power to captivate thousands with their voices on stage, they also need to show the humility to serve another star's shine. This is a delicate balance that requires both a strong ego and the ability to control that ego.

One of the most striking moments in the documentary is when Merry Clayton recounts recording her chilling vocal for The Rolling Stones' "Gimme Shelter." Called to the studio in the middle of the night, Clayton strained her vocal cords while recording the unforgettable "Rape, murder! It's just a shot away" scream. That moment is proof of how a backup singer can pour their own soul into a song and take it to the next level.

Darlene Love, despite being the powerful voice behind countless hit songs in the 60s, her name often went unmentioned in the recordings. While her voice was known by millions, her face was not recognized. Her story is also an indicator of how the industry could exploit talents in the background.

Many famous stars began their careers as backup singers. Names like Cher, Whitney Houston, Mariah Carey, Elton John, and Luther Vandross learned the intricacies of the profession by singing for other artists in studios or on tours. This experience gave them invaluable studio discipline and musical knowledge.

A backup singer's life is one of constant travel, long rehearsal hours, and waiting backstage. But it also offers priceless experiences like sharing the same stage with the world's greatest artists, making music for tens of thousands of people, and being part of a team. There is often a strong bond of friendship and solidarity among backup singers.

They are the invisible skeleton of a song. They support the lead singer's performance, fill the harmonic gaps, and give the choruses that unforgettable power. Their contribution is often not consciously heard, but their absence is immediately noticed.

The next time you listen to a favorite song, listen not only to the main vocal but also to the supporting voices behind it. Try to notice how those harmonies add richness to the song, how those response vocals create a dialogue.

Because the real magic of music lies not in a single voice, but in the harmonious and powerful relationship that voices establish with each other. Backup singers are the silent architects of this magic.

Stardom may always be 20 feet away for them, but their voices are right at the heart of the music we love, and they will continue to live there forever.