It has become routine for Gretel Colomé to finish her shift, get in her car, and cry. A Cuban anesthesiologist and emergency physician who works in the ICU in a hospital in Barcelona, Spain, Colomé rides home after exhausting nights treating COVID-19 patients, and also serving as the connection between the bereft and the loved ones they lose without the possibility to hug them goodbye.

Colomé is often accompanied by songs by X Alfonso, an artist who she has seen perform in Havana and whose career she has followed since he debuted with his fusion of hip hop, jazz funk and Afro-Cuban music; songs that have made her cry harder, and also helped her find hope. “I love his music and his message,” Colomé tells Billboard by phone.

Alfonso uses butterflies as symbols of rebirth and connection in the lyrics of the songs from his new album, Inside, which he has been releasing as a series of singles since late last year. Pop art images of butterflies are the motif for the songs’ cover art. In a video for the song Siento Que, spray-painted butterflies appear on the streets and buildings of Havana.

Earlier this month, at the height of the crisis -- over 22,000 people have died of coronavirus causes in Spain -- Colomé came home to her usual after-work tasks of showering and washing her clothes, a routine repeated so often in a state of total depletion that, she says, she feels like a robot. That day, like she often has, she put on X Alfonso’s song “Siento Que,” which talks about “a new dawn returning to draw the hope that one day left here.”

“The song really brings together so many things I’ve been feeling,” Colomé says.

Looking through photos of members of her family who live in Italy for comfort, Colomé had an idea. She suggested to her nephews, bored at home, that they should draw butterflies, while listening to X Alfonso. She drew some too; drawings of butterflies soon made their way to the hospitals, to the walls of the children’s ward and also onto surgical masks.

Though she says she’s not a big social media user, Colomé decided to initiate her own butterfly effect by creating an Instagram Challenge to spread the comfort that Alfonso’s songs and the simple act of drawing butterflies had given her.

“We are all living hard and sad days,” she said in a message on Instagram. “All of the health workers, doctors, hospital cleaning workers, ambulance drivers, firefighters, pharmacy and supermarket employees are working beyond our limits, but we continue to be here for you.”

In the video she posted to announce the Stop COVID Mariposa Challenge, Colomé sits in hospital whites in front of a screen playing Alfonso’s “Siento Qué” video.

The challenge consists in drawing a butterfly inspired by Alfonso’s own art, together with the words, in any language, “keep fluttering your wings until we can fly together again.”

Colomé also suggests that children and adults listen to Alfonso’s songs while “working, cooking, reading, working out, dancing or even during sad moments.”

Drawings from challenge participants in Spain, Italy, the UK, South American countries and the United States have been posted on Colomé’s Instagram, together with a video of the first ICU patient to conquer the virus at the hospital where she works, and photos of dancing hospital personnel.

“The challenge that Doctor Gretel is doing is a lesson about the power of music,” X Alfonso tells Billboard from Havana, which is also on lockdown. “That songs and their messages can do incredible things like this. You never know the dimension and transcendence that power can have until you see something like this that can reach all over the world…[provoking] feelings that make you think and understand things that you never did before, especially during these moments we are living because of COVID-19.”

Check out Gretel Colomé’s Mariposa Challenge here, and watch X Alfonso’s “Siento Que” video that inspired her below.