A lot of Phil Collins' biggest songs were ballads, but Collins was known for the occasional uptempo number, too – like "Sussudio," the second single (and second No. 1 hit) from his wildly successful 1985 solo LP No Jacket Required.

The title may not have made a lot of sense – in fact, some people are still trying to figure it out today – but that didn't keep the song's infectious riff from dominating Top 40 radio during the first half of the year. It reached the top of the Billboard Hot 100 on July 6, 1985.

Blending Collins' love of Motown R&B with his fondness for modern production techniques, "Sussudio" places an insistent, synth-driven arrangement (programmed by David Frank, one-half of the System of "Don't Disturb This Groove" fame) alongside some percussive, instantly memorable brass work from the Phenix Horns – who were well known for their appearances on songs by Earth, Wind & Fire and a number of other artists. It proved the perfect combination for a set of lyrics about old-fashioned, schoolyard-style infatuation with someone you don't even know. That was perhaps a bit of an odd topic for an artist who was in his 30s and on his second marriage, but effective nonetheless.

And as for that nonsensical-sounding title? As Collins later admitted during an episode of VH1 Storytellers, it was supposed to be temporary.

"I started to sing into the microphone, and this word came out, which was 'sus-sussudio.' It just literally came out, at the time," Collins recalled. "I kind of knew I had to find something else for that word, then I went back and tried to find another word that scanned as well as 'sussudio,' and I couldn't find one, so I went back to 'sussudio.' Then I thought 'Okay, let's give it a meaning. What is it?'"

Watch Phil Collins Perform 'Sussudio'

The lyrics, as he pointed out, "are based on this schoolboy crush on this girl at school," so connecting them to the title simply meant naming the song's object of affection Sussudio. "My older daughter's got a horse called Sussudio," Collins added with a laugh, "and I'm sure there are children all over the world with the name Sussudio, so I apologize for that."

Our (admittedly cursory) research didn't turned up any evidence of children named Sussudio. But the word has lived on in the cultural lexicon, as evidenced by its multiple definitions in the Urban Dictionary. (One was inspired by the song's decidedly NSFW appearance in Bret Easton Ellis' American Psycho book and movie.)

And through it all, "Sussudio" has remained an incredibly catchy (albeit totally '80s) celebration of the irresistible anticipation of attraction.

Genesis Solo Albums Ranked

Projects recorded apart from one another allowed members of Genesis to explore areas of their songcraft that might have gone forever undiscovered.

See Phil Collins in Rock’s Craziest Conspiracy Theories