When Gretel Colomé finishes her shift, she gets into her car, turns on the radio and starts crying. Colomé is an anesthesiologist and battles in the ICU of a hospital in Barcelona to save the lives of patients suffering from COVID-19 in a country that has more than 24,000 deaths and 213,000 infections, despite the contagion progressively decreasing. 

Her work inside the hospital is beautiful, but also terrible: the Cuban woman is a bridge between the patients and their families, she keeps the latter informed and tries to relieve both from the extreme harshness imposed by distance. 

As she drives home, the songs of X Alfonso fill her car. He's a well-known Cuban artist she adores and one she's followed since his debut with his fusion of hip hop, jazz-funk and Cuban music. His songs make her cry more, but they also fill her with hope. 

"I love his music and his message," she told Billboard. 

While for many the butterflies represent the chaos of our system with their flapping wings, for Alfonso, they are symbols of rebirth and they are the protagonists of the lyrics on his new album, Inside, which he released at the end of last year. 

These beautiful insects born from the chrysalis are present on the album cover and in video clips such as for Siento Que, where they are painted on buildings in Havana.

At the beginning of April, Gretel returned home one night exhausted from the long struggle in the hospital, took a shower and listened to Alfonso's Siento Que, which talks about "a new dawn that redraws the hope that one day left here".

"The song really brings together so many things I've been feeling," she said.

Then she had an idea: she proposed to her nephews, who live in Italy, to draw butterflies while they listened to X Alfonso together. 

Soon after, there were butterflies decorating the walls of the hospital's pediatric ward, and even drawn on the surgical masks.

The initiative was so successful that Colomé decided to launch her own "butterfly effect" and created an Instagram challenge where users had to draw more butterflies inspired by X Alfonso's song. 

"We are all living hard and sad days," she wrote. "All health care workers, doctors, hospital cleaners, ambulance drivers, firefighters, pharmacy and supermarket employees are working beyond our limits, but we are still here for you."

In the video she posted to publicize the Stop COVID Mariposa challenge, the doctor appears in the hospital in front of a screen that plays the singer's video and challenges us to draw these insects along with the line from the song "keep flapping your wings until we can fly together again".

Colomé suggested that children and adults listen to X Alfonso's songs while "working, cooking, reading, exercising, dancing or even during sad times."

Since the challenge began, Gretel Colomé has received drawings from all over the world that she publishes on Instagram along with luminous videos, such as the first ICU patient in her hospital who survived the coronavirus or her colleagues dancing. 

Even X Alfonso spoke about the initiative from Havana.

"The challenge that Dr. Gretel is giving is a lesson about the power of music," said the musician from the quarantine. "Songs and their messages can do incredible things like this. You never know the dimension and the transcendence that can until you see something like this that can reach everyone... [provoking] feelings that make you think and understand things you've never done before, especially in these moments we're living because of COVID-19," he added.

Are you up to the challenge? Draw your butterflies and make them fly HERE.