In a neighbourhood bar on a cobbled square in Lisbon's historic working-class Alfama district, an eclectic mix of punters pull up little wooden stools around a dozen intimately lit tables.
On the walls hang guitars and an old piano stands ready to accompany that evening's music, be it fado, Cape Verde morna, Brazilian bossa nova or a delirious fusion of all of these and more.
Unassuming it may be in appearance but the Tejo Bar is a rich musical melting pot, each day infused with a different style and atmosphere depending on the musicians who pass by.
So instrumental has it become on the Lisbon music scene that US superstar Madonna counts among its fans, crediting the little bar in her adopted home city for setting the stage for her upcoming, new album.
"Inspiration for my new record all started here in Lisbon, at Tejo Bar," the 60-year-old queen of pop said on Instagram, of her "Madame X" album, set for release on June 14.
- 'Inspired' -
Madonna moved to the Portuguese capital in 2017 so that her son David Banda -- one of four children adopted in Malawi -- could attend the Benfica football academy, where he remains enrolled.
It did not start particularly well.
"I thought it was going to be super fun and adventurous, but then I found myself just going to school, picking up kids, and going to soccer matches and really being 'Netty-No-Mates', and I got a little bit depressed," Madonna told the MTV music channel.
Things changed though after she began meeting artists and musicians in Lisbon -- the capital of a vast former colonial empire including Brazil -- and then discovered the Tejo Bar.
"Lisbon is a melting pot of cultures... musically, from Angola to Guinea-Bissau, to Spain, to Brazil, to France, to Cape Verde," the singer, who has six children, told MTV.
"I had the pleasure and honour to meet musicians from all these places and be inspired by their music and let it influence me.
"And that's how all these songs came to be" on the "Madame X" album, she added.
- Playing for Madonna -
Co-owner Mira Fragoso, a Brazilian former actress, is proud of the Tejo Bar's creative force, in what was once a traditional district and is now increasingly popular among foreigners and tourists.
"Offering a space that inspires artists like Madonna fills me with joy," she told AFP.
Customers also include locals, writers, painters and students, while musicians describe improbable musical encounters such as a pianist playing a Jacques Brel song with an Austrian violinist or a Japanese guitarist accompanying a Portuguese singer.
Madonna met 33-year-old Brazilian pianist Joao Ventura through the Tejo Bar.
"She was sitting in a corner that evening," Ventura recalled.
At the request of a friend, he sat down at the piano and played a bossa nova piece interlaced with strains of Beethoven's "Moonlight Sonata".
"The next day, she called me to say she liked it, and proposed performing with me in New York," he said, telling AFP how, at first, he could not quite believe he was talking to Madonna.
He said that the pair met three times to rehearse at Madonna's house in Lisbon, before he played piano for her on three songs performed on stage at the 2018 Met Gala.
- 'Cultural diversity is everywhere' -
Portuguese singer Dino D'Santiago, who is of Cape Verdean origin and performs in both Portuguese and Creole, has guided Madonna around Alfama's narrow streets.
"The cultural diversity here is not just in the ghettos. It's everywhere," the 36-year-old told AFP.
He also introduced the superstar to his batucadeira orchestra of Cape Verdean singers and percussionists, some of whom will accompany Madonna on her tour that kicks off in September and includes a concert in Lisbon in January.
And D'Santiago brought together Madonna and Kimi Djabate, an Afrobeat musician from another former Portuguese colony, Guinea-Bissau.
He recorded a bonus song for her album titled "Ciao Bella".
One evening at the B.Leza African club in Lisbon, Madonna met singer-dancer Blaya.
The tattoo-covered artist said that she believed Madonna's children had introduced the superstar to Blaya's hit song "Faz Gostoso" and the pop diva herself has recorded a cover of it in a duo with Brazil's Anitta for her new album.
- The Madonna effect -
Fado singer Vania Duarte, 34, also benefited from the Madonna effect after singing for the star at her fado hall, the Casa de Linhares. Madonna said on Instagram that she found her style inspiring.
Madonna's presence has not been without controversy, notably when the city council was accused of giving her special treatment by renting her a 15-spot car park in the packed capital, provoking anger across the political spectrum.
And in the western Sintra suburb, her production team was barred from staging a scene with a horse at a 19th-century manor.
"There are some things money cannot buy," Expresso weekly newspaper quoted Sintra mayor Basilio Horta as saying at the time.
But the benefits to tourism and the city's image are not lost on the country's Socialist government.
State Secretary for Tourism Ana Mendes Godinho told public radio Antena 1 in 2017 that Madonna was a sort of "business card" she used when promoting Portugal abroad.
And sources say that the US pop diva has been granted a special residency permit reserved for foreigners whose presence is deemed in the "public interest".