Time waits for no one, and one jolting reminder of this is when former child and teen stars become middle-aged adults.

Today, Christina Aguilera turns 40 years old, and if you’re a millennial of a certain age, this is mind-blowing. The girl who sang “Genie in a Bottle” is now a grown-ass woman.

Christina’s career has always been an interesting one, and I often wonder what it would’ve looked like in a world where Britney Spears didn’t exist. Would she have been less successful if Britney hadn’t upended popular music months prior (thereby creating frenzied demand for teenage white girl performers)? Or would she have achieved Britney-level fame? It’s impossible to say for sure, but through constant comparison in the press, people were led to believe that the Mickey Mouse Club alums were in competition (which isn’t implausible) and, in fact, similar (which they weren’t). Aside from being close in age and having blonde-dyed hair, they were decidedly different artists from the get-go.

First of all, and with all due respect to Brit, Christina was a true vocalist, with some even calling her the “new Mariah” at the time of her debut. Also, Christina’s sound always skewed more R&B — even on her debut album, which many would describe as “pop.”

As the years went by, Christina would demonstrate a willingness to go places that Britney wouldn’t — and, in some cases, couldn’t — with her sound and look. The comparisons never completely went away, but today, it is clear that Christina Aguilera was always more than just Britney 2.0.

Below are my four favorite tracks from Christina’s catalog. Join me in celebrating this icon.

“Can’t Hold Us Down”

“Come on Over (All I Want Is You)”

“The Voice Within”

“Lady Marmalade” (with Mya, Pink and Lil’ Kim)

If you asked me to list the 10 best recorded vocal performances of all time, there’s a strong chance that “Breakin’ My Heart (Pretty Brown Eyes)” by Mint Condition might make the list. Because Stokley Williams — the lead singer of the group — was SINGING-singing. Sangin’, in fact.

Released in November 1991 as the second single from the group’s debut album, Meant to Be Mint, “Pretty Brown Eyes” takes us back to a time when the voice was the centerpiece of most popular R&B songs. These days, we’d be lucky if we can get a hum out of Jhené Aiko or The Weeknd.

Co-written by Stokley and bandmates Larry Waddell and Jeffrey Allen, “Pretty Brown Eyes” would go on to become the group’s biggest hit, peaking at No. 6 on the Billboard Hot 100. And like every other timeless composition, the song would be sampled on numerous songs over the years, including Amerie’s “Pretty Brown” (featuring Trey Songz) and Remy Ma’s “Melanin Magic” (featuring Chris Brown).

Long before he was getting caught up in festival scams, Ja Rule was a bonafide hit-maker. And one thing about them hits? They all aged well.

Most would agree that Ja’s signature hit is “Always on Time” (featuring Ashanti), the second single from Pain Is Love and his sole No. 1 as a lead act — he has two as an assist on a pair of J.Lo singles. The song is also a signature for that moment in popular music: Ja Rule was everywhere, and in the coming year, so would Ashanti. Also, the musical craftings of Irv Gotti and 7 Aurelius (the song’s co-writers) were the standard.

“Always on Time” was actually supposed to feature Brandy. And you know what? I could totally hear it. However, it was only right that Ashanti got her moment to shine — especially after singing the hooks on the aforementioned J.Lo hits (sans credit). Click play.

If you’re looking for a pick-me-up, the new version of Mariah Carey’s “Oh Santa!” might do the track. This new version — we’re not calling it a remix because Mimi isn’t — is a part of Mariah Carey’s Magical Christmas, the Apple TV+ special that dropped at midnight. And this time, Mariah is joined by Jennifer Hudson and none other than Ariana Grande, the reigning queen of the charts and a woman often called “the new Mariah.”

It is well-documented that Mariah hated that, but over the years, the two artists played nice on social media. And now, here they are, singing together and even matching whistle notes.

Overall, the song isn’t made better by the additions, but seeing all three singers together is something to be excited about. And including Jennifer Hudson was definitely a smart way to distract from the Mariah vs. Ariana comparisons that will inevitably happen. Click play.

For years, Mariah shaded Ariana, but luckily, Ariana knew to never retaliate.

There are certain songs that immediately put you in a good mood, and for me, Daniel Bedingfield’s “Gotta Get Thru This” is one of them. And today happens to be his birthday, so what better day to revisit this chune?

Released in November 2001 and written by the singer himself, “Gotta Get Thru This” is peak UK garage and a prime example of how the Brits generally do it better when it comes to EDM. I’ll admit that I wasn’t in love with this song when I first heard it, but a few months later, I became obsessed and the rest is history.

“Gotta Get Thru This” is about a girl Daniel fell in love with but couldn’t pursue due to distance. He couldn’t stop thinking about her, and now we have a bop because of it. The song would go on to top the UK charts and crack the top 10 in the US.

Ooh, but can you do Shirley? Why surely.

“Attack of the Name Game” is a cute interaction with a 15-year-old Stacy Lattisaw and an alien who landed on earth ready to drop bars. No one knows how or why that happened.

Released in 1982, the song is something of an updated version of Shirley Ellis’ “The Name Game.” While Stacy is a singer, “Attack of the Name Game” is entirely rapped, which was a somewhat progressive and, dare I say, edgy move in 1982.

Perhaps that edginess was part of the theme for that era. The parent album for “Attack” is called Sneakin’ Out, and below was its album cover.

What a time.

Written by Narada Michael Walden (with Randy Jackson from American Idol on bass), “Attack” peaked at No. 70 on the Billboard Hot 100. While most songs that peak that low on the charts are forgotten forever, “Attack” would return as a sample in 1999, when Mariah Carey used that beat (entirely unchanged) for “Heartbreaker,” her 14th No. 1 on the Billboard Hot 100.