I Will Always Love You

The harmonic structure is deceptively simple, relying on the '50s progression (I-vi-IV-V) which provides a stable, emotive foundation. Its distinctiveness lies in the dramatic 'truck driver's gear shift' modulation from A Major to B Major, which is one of the most famous examples of key change in pop history. This shift, combined with the a cappella opening and the gospel-inflected vocal delivery, transforms a standard ballad progression into a high-intensity power ballad.

Dolly Parton wrote the song as a farewell to her mentor and professional partner of seven years, Porter Wagoner, after she decided to leave 'The Porter Wagoner Show' to pursue a solo career. She wanted to express her gratitude and love despite the professional separation.

Whitney Houston's R&B reimagining of Dolly Parton's country original became a global phenomenon as the lead single for The Bodyguard soundtrack. It is celebrated for its technical mastery, iconic a cappella opening, and its 14-week reign atop the Billboard Hot 100.