Bertold Brecht did not know the River Nervión or the factories that lined the waterside. He hardly knew where the city was, but he liked the way the name sounded. Bilbao: with its rounded vowels and elastic consonants. That was the start he needed; later came the old moon, the bar with its free-flowing brandy and the grass under the floorboards. This German dramatist and poet, working with the composer Kurt Weill, dedicated a song to the Basque town that has since been sung by a thousand artists, in every style from jazz to Christmas carol.

Bilbao Song was written in 1929 for the musical Happy End, which was commissioned from the songwriters after the success of their previous collaboration, The Threepenny Opera, of 1928. Brecht and Weill’s plot deals with the struggle of good and evil, told through the story of a romance between two very different people: a Salvation Army worker and a gangster. It also offers a dose of social criticism combined with a hint of Marxism, a blend that can be seen in the previous joint work by the two left-wing intellectuals. For them, Bilbao was the place where youth was left behind, the end of innocence.

However, most likely neither of the two had ever visited it. There is no record of either one or the other spending any time in Biscay, or any biographical information to link them with its largest city. “Brecht had seen the name on a map, and he liked the way the letters looked. He read the name out loud and he liked it even more. He wanted to make the sound of that place, which was alien to him, familiar though the music of his song,” writes Vicente Molina Foix. It was chance that made the writer turn this city into an immortal song, never knowing that, as often as not, the old Bilbao moon is hiding behind the clouds.