ABBA have returned to their storied past with “Just a Notion,” the third track to appear from the band's upcoming reunion album Voyage.

It was originally written in 1978 for the band’s Voulez-Vouz LP, but then left off the final release. ABBA updated the instrumental tracks, but retained the original vocals from 43 years ago. “Just a Notion” can be heard below.

Bjorn Ulvaeus admitted he had no idea why “Just a Notion” was didn't make the original track listing. “It’s a good song with great vocals,” he said in a news release. “I know that we played it to a publisher in France and a couple of other people we trusted, and as far as I can remember they liked it very much. So it’s a mystery and will remain a mystery.” He described “Just a Notion” as a “ridiculously happy song,” adding: “Hopefully it will cheer you up in these dark times!”

ABBA released two new tracks in August, "I Still Have Faith in You" and "Don't Shut Me Down,” and confirmed the Voyage album would arrive on Nov. 5. They also announced a concert residency in London that features digital versions of the members performing alongside a live band, presented in a custom-built venue.

“In a way, ‘Just a Notion’ demonstrates what we plan to do with ABBA Voyage in 2022,” Ulvaeus added. “There, we will have a live band playing, but all vocals will be from the old recordings.”

Bandmate Benny Anderson earlier described ABBA's tech-driven comeback as “sailing in uncharted waters. With the help of our younger selves, we travel into the future. It’s not easy to explain but then it hasn’t been done before. When you come to the arena you will have the four of us together with an absolutely glorious 10-piece band. And even if not in the flesh, we will be right there.”

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