A little over a year ago, Teddy Geiger revealed something important on Instagram, something that would shape the rest of her life. "I'm transitioning," she wrote to answer a fan's question about her changing appearance. "Love it or hate it this is who I have been for a looooong time."

The declaration kicked off a new era for Geiger, the songwriter and singer who had spent years behind the scenes penning music for One Direction, 5 Seconds of Summer, and Shawn Mendes. In fact, three songs Geiger and Mendes wrote together — "Stitches," "Treat You Better," and "There's Nothing Holdin' Me Back" — hit the top 10 and quickly became Mendes's signature tracks. But that's all part of Geiger's career.

Her personal news precipitated a string of revealing, illuminating interviews that focused on her: her own music, her identity, and her years-long path from teenage pop-rock wunderkind to celebrated songwriting maestro. In 2006, Geiger hit as a talented solo artist with "For You I Will (Confidence)," released a debut album called Underage Thinking, and ventured briefly into film and TV roles all before age 21.

As she recapped to The New York Times earlier this year, though, she found the music-industry machine exhausting. "Having a hit is fine, but doing the work is what I want," she said. "I get more excited the day of creation than once it's big."

In 2018, after years of quiet retreat and private writing, Geiger was once again eager to share her creation. Teddy became teddy<3, a fun moniker used to package her own new solo recordings, which culminated in a personal, wildly technicolor new album called LillyAnna. She made some public appearances at awards shows and industry parties. And notably, she teamed back up with Mendes for the most ambitious album of his career. Here's what happened during the highest-profile, most creatively enterprising year of Geiger's life.

There's Nothing Holdin' Them Back

Before Mendes dropped his self-titled album in May, he gave us a taste of his newfound maturation on the advance singles "In My Blood" and "Lost in Japan" — two Geiger co-writes that thrusted Mendes's star forward both musically and thematically. The former mines the 20-year-old's struggles with anxiety while the latter playfully saunters into the arena of sex.

Geiger co-produced those as she did for 11 of the album's 14 tracks, giving Shawn Mendes a unified, holistic aura of confidence. It's a representation of Mendes fully coming into his own as a performer, writer, and all-around talent, one his recent Rolling Stone cover story folds into a larger examination of his fame. It's also hard not to equate that sonic self-assurance to Geiger's own clear path forward, which began after letting the world know who she is.

One of Mendes's idols is John Mayer, a pop figure who likewise was hardly ever seen without a guitar in his early years. Geiger's "For You I Will" sounded like it fit that Mayer mold, too, with its hushed vocals and strummed acoustic chords, so there's a bit of undeniable synergy in their creative partnership. The best part now, of course, is how Geiger's sound has matured well beyond that, adding splashes of psychedelia and a coat of early 2000s New York grit. You don't necessarily hear it on Shawn Mendes — though the roomy, pumped-up claps on "Queen" are steps forward — but it's all over LillyAnna, her lush reintroduction as teddy<3.

Under The Blue And Brand New

In fact, LillyAnna's atypical arrangements are precisely what make it so endearing. She still strums chords — you can hear as much on the glam title track and the panoramic "Under the Blue" — but the songs they serve frequently sound sideways. Geiger's voice is rarely present without a layer of distortion or reverb and often even partially obscured in the mix. A lot of the effects-heavy tracks, like moody instrumental "8" and frenetic indie pop bop "Wishing (And Hoping)," sound lifted right from a hidden SoundCloud page. In a way, they were; Geiger spent a portion of 2018 tweeting out demo versions of dozens of tracks she'd assembled over the years.

But LillyAnna, named for a persona she'd once used online, isn't just a collection of ideas. The songs date from 2011 or 2012 up until right before she transitioned, as she revealed to Zane Lowe in September. Despite that, it's easy to hear LillyAnna — with its burying of solid pop foundations under whirling keyboard textures, layers of post-punk bass lines, and even a brief funk detour (!) — as a reemergence of the new teddy<3. And it sounds exciting.

So, too, does a recent acoustic "Under Pressure" cover where she plays the David Bowie to Mendes's Freddie Mercury, and a reportedly forthcoming track for singer Olivia O'Brien that Geiger cooked up while using a beer can as an instrument at a party. "I just feel more open," she said in that New York Times interview. For Geiger, it's a resurfacing. But for teddy<3, it's just the beginning.