U2 have a lot going on right now: A new album of re-recordings, a Disney+ special with David Letterman, a Vegas residency that got announced in a Super Bowl ad. That means that Bono and the Edge are on the promo trail right now, and they recently paid a visit to the BBC’s Radio 2 Piano Room, the same place where Jessie Ware covered Cher’s “Believe” last month.

In the Radio 2 Piano Room, U2 paid tribute to their fellow pop icons ABBA. U2 are longtime ABBA admirers; back in 1992, ABBA’s Björn Ulvaeus and Benny Andersson joined U2 onstage in Stockholm to perform “Dancing Queen.” In their BBC session, Bono and the Edge played acoustic versions of a few of their classics, with the BBC Orchestra backing them up. Bono also talked a bit about being scared to embrace great pop music when he was a teenage punk but gradually understanding how powerful those songs were.

That all led up to Bono and the Edge doing their own slowed-down acoustic version of ABBA’s 1975 classic “SOS.” The Edge said that the duo “found a Johnny Cash angle” on the song, since he doesn’t think that they can get too pop, and Bono introduced the cover as “a marketing gimmick from U2.” Below, watch the cover and the video for the ABBA original.

Meanwhile, here’s Bono and the Edge doing “Vertigo” acoustic:

You can hear the full hour with Bono and the Edge here.