Hardly a new track, the source I have says it was made "circa 1973," around the time of There Goes Rhymin' Simon. So perhaps the correct term would be "newly unearthed." According to Jay from South Africa, it appeared on YouTube "for the first time ever" in May of 2023.
Here is the link: https://www.youtube.com/watch?v=RUhruae-9JE
The real question is... is it even a song? "Billy Boy," more than six minutes of it, seems more of a melody in search of a lyric, which itself seems very much a rough draft. The result is nothing one could be expected to release, except on a compilation of demos and out-takes.
Another question is... what is Simon even singing? Since the vocals seem only to be placeholders for something else, much of the vocals are mumbled and garbled, with only the meter and melody being prioritized.
An early draft of the song "Yesterday," by the Beatles, was called "Scrambled Eggs"; those two utterances share nothing but their meter (a dactyl), but that is all that was required at that point.
What we have here is even less... a series of cliches that meet the requirements for the meter: "you've been gone so long," "I've been down in the morning," "I've been waiting for the light to come," ... and variations on "sun don't ever shine," made to rhyme with "my heart, my valentine." The rest is-- to me, at least-- unintelligible.
There is no other instrumentation beyond Simon's guitar, but there are backing vocals, a small chorus of women (sounds to me like three). They sing "I believe it, I believe it" over and over. It's a close harmony, presaging the backing vocals on "I Know What I Know."
As to the likely source of this exercise, "Billy Boy" is the title of an old folk tune, structured as a duet. The song is often used to teach a beginner to play the guitar.
The song begins with the speaker asking Billy where he has been. He says he found a girl he'd like to marry but, sadly: "She's a young thing, and cannot leave her mother." The first speaker asks several follow-up questions-- but after answering each, Billy adds that same line, resigned to have to wait until she is old enough for courtship.
Here, Simon seems to be trying to update this folksong. He addresses a "Billy Boy" who has returned, and there seems to be a heartbreak theme-- "valentine" is repeated often. So some of the elements are similar to the old song.
In his time with Garfunkel, Simon explored many earlier folksongs, which resulted in the well-known "Scarborough Fair" but also lesser-known recordings of versions of "Barbara Allen" and others (for a comprehensive list, see the Page on this blog tilted "Songs Mistakenly Attributed to Simon"; the traditional numbers are near the top of the list).
I have a whole album of rock songs, from "Midnight Special" to "Sloop John B," that were based in old folksongs, collected by Alan Lomax for the Smithsonian Institute's Folkways album series. Many other songwriters sought similar inspiration in traditional American, British, or other folksongs.
So it is not unlikely that, around the time of his second (post-S&G) solo album, Simon went back to the well of traditional folksong for inspiration, came upon "Billy Boy," and thought, "Let's see what I can do with this."
The answer? Not a whole lot. Oh, well. Failed experiments are necessary, on the road to successful ones.
This blog aims to be comprehensive, while acknowledging the technical unlikelihood of that result (thence the * in its title). Still, in the name of completeness, I am including it here, on Every Single Paul Simon Song... while also acknowledging that it may not even be, technically, a "song" as such.