Rowe brought in session musicians Arthur Greenslade on organ and Bobby Graham on drums, since he considered the Them members too inexperienced.

There remains some dispute about whether Millings and McCauley were actually miked, but Alan Henderson contends that Them constituted the first rock group to use two drummers on a recording.

[9][10] Decca Records released "Gloria" as the B-side of "Baby, Please Don't Go" in the UK on 6 November 1964, with only the latter reaching the singles chart.

[12][13][14] A year later, after the release of a cover version of "Gloria" by the Shadows of Knight, Them's original entered the national Billboard Hot 100 chart.

[11] One explanation for the timeless popularity of the song was offered in AllMusic's review by Bill Janovitz:[11] The beauty of the original is that Van Morrison needs only to speak-sing, in his Howlin' Wolf growl, "I watch her come up to my house/She knocks upon my door/And then she comes up to my room/I want to say she makes me feel all right/G-L-O-R-I-A!"

"Gloria" was rated number 69 on Dave Marsh's list in the 1989 book The Heart of Rock & Soul: The 1001 Greatest Singles Ever Made.

"[28] In his book Rock and Roll: The 100 Best Singles, Paul Williams said about the two sides of the "Baby Please Don't Go/Gloria" recording: "Into the heart of the beast ... here is something so good, so pure, that if no other hint of it but this record existed, there would still be such a thing as rock and roll ... Van Morrison's voice a fierce beacon in the darkness, the lighthouse at the end of the world.