U2 has recorded a handful of instrumentals over the years–mostly, but not exclusively, in the early years. Today’s topic is very nearly one of those instrumental tracks, but for a very few lines of singing. That’s enough by itself to make this song noteworthy in U2’s catalog. What makes it special, though, and almost entirely unique is the source of what vocals there are in “Endless Deep. That source is U2’s bass player, Mister Adam Clayton.

After listening to “Endless Deep” many years ago and learning who was singing, my first thought was “there’s a reason he doesn’t sing more often.” Adam has a lovely speaking voice (As evidenced on the only other example of his recorded vocal work, “Your Blue Room,”) but when it comes to singing…well, he ain’t no Bono. That’s OK, I think. There are four members of U2, and they all have valid things that they add to the overall sound of the band. Adam’s just happens to be done with his fingers instead of his vocal chords. The fact that Adam did do this little bit of singing proves several things to us. Firstly, that they gave the job of vocalist to the guy best suited for it, even if they didn’t know it at the time. Secondly, Bono is very generous to allow others to step in and sing lead from time to time. Thirdly, it is an interesting and worthwhile path to go down to hear voices on a U2 record other than Bono and sometimes Edge. It mixes things up in a good way.

As one might expect from a song that seems to have been a pet project of a bassist, “Endless Deep” is funky and groovy and definitely bass-driven. There’s some nice piano and a quick little rhythm that Larry beats out on the tom-tom, and even a little bit of guitar and synth, but Adam’s bass takes command early and doesn’t give it up until the exercise has run its course. It’s not really danceable (like, for instance “Two Hearts Beat As One,” the song that this was a B-side to) and it is a little too weird to hold a place as a straightforward rock song, so I have to conclude that this was mostly an experiment. To determine what, I have no clue. Just what it would sound like to let Adam take the reins, I expect. The result is a little bit ethereal, a little bit poppy, a little bit rock, and a lot strange. It also sounds exactly like it came from 1983, which is another element that sets it apart from the rest of U2’s music–very little of their music sounds dated in such a way.

Perhaps it won’t come as a surprise that “Endless Deep” has never been performed live in front of an audience. U2 doesn’t often play instrumentals (or near-instrumentals) live, especially once they had enough songs in their repertoire to avoid it. The last time they did that was with “Return of the Stingray Guitar” in 2011, which was used to open some shows. I’m chuckling to myself to think of U2 opening a show with a live performance of “Endless Deep.” Maybe that’s happened in some strange parallel universe, but not in this one, and I say that we should all be grateful for that.