Which Led Zeppelin song is reputed to have popularized the hard rock genre?

Whole Lotta Love

"Whole Lotta Love," released in 1969 on the album "Led Zeppelin II," is often cited as one of the most influential songs in the development of the hard rock genre. With its powerful guitar riffs by Jimmy Page, explosive vocals by Robert Plant, and innovative production, the song set a new standard for rock sound. This track not only helped cement Led Zeppelin's reputation as one of the leading forces in rock but also played a key role in defining the sound and attitude of hard rock in the 1970s. The song continues to be a major influence for musicians in rock genres and beyond, testifying to its lasting impact on popular music.