An Italo Disco song from 1985 by one Marco Ceramicola under his pseudonym of Manuele Pepe, Shadilay achieved unexpected fame in 2016 when it became some sort of a meme.
To understand why this is, this might take some time, because it involves rummaging through several other 4chan memes and their geneses. Basically, it all started when cartoonist Matt Furie drew Pepe the Frog in 2005, thus germinating a whole heap of ubiquitous (on imageboards at least) reworks of said cartoon frog. It began with "Feels Good Man," and then evolved into Sad Pepe (a frog looking glum), Mad Pepe (a frog looking angry with a gun), Glad Pepe (a smiling frog), Smug Pepe (a frog with a biiiig smile and scratching its chin - easily the most ubiquitous Pepe as it became used to denote schadenfreude which is what chan culture basically runs on), and many more such as Beta Uprising, REEEEEEEEEEEEE, Trump Pepe, and suchlike.
The other inspiration was how in World of Warcraft (a game I do not play because I have a life) "lol" coming from Horde players when you're an Alliance player is wordfiltered into "kek" after how Korean Starcraft players would go "Zerg rush kekekekekekekeke" (kek being the Korean way of onomatopeia-ising laughter). Anyhow. Some anon noticed that the ancient Egyptians had a frog god called Kuk who was sometimes referred to as Kek, and therefore decided that Pepe the Frog was the reincarnation of Kek and thus created a pseudo religion and/or ethnicity, Kekistan, in which Kek was the only true god and Pepe was His prophet and eating chicken tenders and not drinking tap water (because of some tabloid trash about how fluoride is making the frogs gay) is the way of worshipping same.
Anons then discovered that the vinyl pressing of Shadilay, by Manuele Pepe, had a frog on the label and therefore was further proof that Esoteric Kekistanism was the only valid religion. "Shadilay" therefore mutated into an equivalent of Islam's "mashallah" or similar.
It then got a bit out of hand and it all ceased to be funny any more, as channer humour does fairly quickly.
The song is fairly good though and quite catchy. There are also some rather good remixes of it on Youtube but the comments sections of same are, of course, an absolute toilet because I. it's Youtube comments, II. it's an outgrowth of a channer in-joke, III. ever since Trump's unexpected election victory of 2016, allegedly partly brought about by memes on 4chan, every other post is either screechy pearl-clutching and accusations of racism or contains the word "cuck."