Khaira Arby, also known as the "Nightingale of Timbuktu" and the "Diva of the Desert," passed away on Sunday at a Bamako hospital.

Her son confirmed the news, saying she had been receiving treatment for heart problems.

Arby, a widely celebrated songwriter and recording artist, had long been popular across the globe and in her home for her powerful raw vocals, as well as her blend of Saharan desert blues with funkier sounds.

She was very outspoken, often using her songs and position to speak out for social issues like female empowerment in Mali.

In 2012, when Islamist extremists imposed sharia law over a large swath of northern Mali, and with it a ban on music, she was a stood in strong opposition.

Her and several other Malian musicians' fight during that arduous time was captured in the documentary They Will Have To Kill Us First: Malian Music In Exile, which OkayAfrica executive produced.

"If you ban music in Mali, or in the whole world, it's like cutting people's oxygen off," Arby said in the documentary.

Once the Islamist militants were pushed back, it was Khaira Arby started an effort to hold the first concert in Timbuktu since the invasion.

"She just got out on the street and started singing with a few local musicians, and everyone just came out of their houses and just started floating towards the sound — it was extraordinary," recalls Johanna Schwartz, the director of They Will Have to Kill Us First.

Khaira Arby's music led her to play festival across the world, from Mali's own Festival Au Desert to Bonnaroo Music Festival in the United States.

She was buried near her family home in Bamako and is survived by a daughter, five sons and 14 grandchildren.

People have been reacting on social media and paying tribute since her passing on Sunday. See some reactions below.