Clap, clap!

Often it’s the unintentional that ignites the most memorable musical moments. In the case of “Beverly Hills 90210,” the theme song’s iconic claps were mere filler for a gap that had composer John E. Davis stumped during a spontaneous all-nighter to churn out a track for producer Aaron Spelling. Turned in just days before the show’s 1990 premiere, the percussive element became more prominent in the revamped opening credits of season two.

“I just didn’t know what to do there when I did the song originally,” says Davis, ahead of the series’ quasi-reprisal BH90210 premiering tonight. “So, I said, ‘I think it would be cool if all of the cast do a hand clap,’ and the director went, ‘I like that hand clap. Let’s have the cast do it along with the music.’ They cut the film to match the music because they loved the clap so much and all of a sudden it became very popular.”

Initially, asked to write the background score for the series’ two-hour pilot, Davis was sent the video tape and immediately struck by the show’s “heart” and contemporary feel. Completing the music for the pilot, he was surprised to get a call from late producer, Spelling, a couple of days out from the premiere.

“Aaron calls and says, ‘We just played the episode for Fox and the executives hate the theme,’” Davis says. “Apparently they had a rock band do it. They never told me who it was and I still have no idea, but he said it didn’t work out and asked, ‘Any way you can get us something by tomorrow?’”

Forgoing sleep, Davis set out to produce a tune which reflected the show’s striking combination of contemporary and wholesome. “It needed to be contemporary, but also have some semblance of heart to it, so I tried to use both those elements. There are two feels – the rock and roll edge first, then at the end it turns a little sweeter, which was my homage to the family values of the show.”

Creating an anthemic mix of guitar, saxophone, synth and piano, Davis presented the track to executives the next morning, who “loved it.”

While today, theme songs are somewhat less prominent, significantly shorter and sometimes don’t air at all, Davis’ creation would become a significant backdrop to the series, which wrapped up in 2000 following 10 seasons. Countless versions are heard throughout each episode, with Davis adapting pieces of the track to fit different moods and storylines. There’s the hilariously chirpy and upbeat version during a scene at the Beverly Hills beach club in season two, followed by the rockier, guitar solo-like spin on it as Brandon and Dylan hike a mountain. Emotional scenes meanwhile leaned on the piano segments, like the slow, dramatic chords as Brenda and Dylan break up (again) in season three.

Davis says the versatility of the song was hugely beneficial in helping elevate storylines. “It may not have been intentional, but fortunately, when I did it originally, I included different sound options, like the edgier rock and roll sound, then the piano stuff. There were always pieces of all that to incorporate into different moods when I needed them. If Dylan got nasty, so did the music!”

Davis even adapted the song to fit different cultural situations, like season one’s “East Side Story” episode, in which Brandon starts dating Karla. Visiting the teen’s Hispanic neighborhood in east Los Angeles, the song – and music throughout the episode – adopted a cultural flare. “They had a special kind of [Hispanic] music which they asked me include,” Davis says. “They were very happy with it and the episode wound up winning an award [for the way it] acknowledged Spanish mannerisms and culture.”

Although it became “harder to keep up” and stay in contact with the young stars as the show exploded, Davis continued to visit the set for scenes which required stronger musical guidance, like a holiday episode where the cast performed “White Christmas.”

The cast was called upon again last year when a promo for BH90210 (in which they portray heightened versions of themselves) debuted, showing them going about their lives while sound effects, like Brandon whacking his alarm clock off, substitute the song’s signature claps.

Those claps were key when composer Brian H. Kim was asked to redo the tune for the revived series. Given a blank canvas to create a new opening, he first attempted an EDM-style remix, before a second take focused on merging ‘90s sounds with modern pop.

“I kept it in the electric guitar style but made it beefier,” he explains. “There are a lot of artists now like Taylor Swift or the Jonas Brothers who are reaching back to the early ‘90s and incorporating that into what pop music sounds like today, and this was a good opportunity to do that. I took some ‘90s-style snare drums, and created a fusion of retro ‘90s and modern-day, to match the fusion happening in the show.”

For the claps, Kim was inspired by tropical house music and added a reverb tail for an echo effect.

As with the original series, the song will feature throughout new episodes, particularly to highlight references to old storylines. Kim says the show will also offer some “throwback” songs and that the cast have all had input when it comes to music – with Brian Austin Green’s musical background particularly evident and valued.

The theme already started its comeback thanks to a Peach Pit pop-up in West Hollywood over the weekend. There,  its opening chords had “90210” devotees lighting up with excitement. The venue further transported fans back to the ‘90s thanks to a play list heavy with the Backstreet Boys, Britney Spears, Rob Thomas, Kris Kross – and of course, the “90210” theme song.

Growing up as “a child of the ‘90s,” Kim is still pinching himself that he’s been getting paid to work on such an iconic part of the era’s pop culture. “It’s funny how many hours of the day I spend thinking about ‘90210,’” he laughs. “Getting to [recreate] a theme song everyone knew, and wake up in the morning and think about Brandon Walsh and Kelly Taylor has been wild.”

Meanwhile, Davis (who wasn’t asked to work on music for the reprisal, nor The CW’s five-season spin-off 90210) feels like “the luckiest guy in the world,” to know the music he created during a last-minute all-nighter is still so loved. “It amazes me that people still hold this show so close. I just hope everybody had a good time with the series because that was the idea.”

We’ll clap to that.