The strumming "Gloria" was released as the lead single from III. The songs on the record focus on three fictional characters: this track's titular character; her son Jimmy Sparks; and Junior Sparks, her grandson.
This track introduces Gloria, the family matriarch who inspired by an actual relative of Lumineers vocalist Wesley Schultz's that was an alcoholic. Here, he sings about a family relationship that struggles with substances. Schultz explained to Radio.com that "Gloria" is a song about "love between an addict and her family."
The cinematic video follows the titular character played by actress Anna Cordell as she battles addiction. We see how her alcohol abuse impacts her husband and young child.
"Whole Lotta Love" was Led Zeppelin's only US Top 10 hit, charting at #4. Many of their songs, including "Stairway To Heaven," were not released as singles, as it was considered bad form in England to make people pay for singles that were on albums.