Positivus is a 3-day annual music festival in Salacgriva, Latvia. Because the location is in close proximity to Estonia, thousands of fans from both countries join every July to see world-renowned bands and artists to perform in a beautiful setting by the coast.

The initiative to perform with Estonian women's choir came from Plant, who is the headliner for the festival.

Triin Koch, the choir's conductor, explained that Robert Plant is a big fan of Veljo Tormis's compositions, especially “Curse Upon Iron“ (Raua needmine), the composer's shamanic masterpiece from 1972.

"'Curse Upon Iron' is part of our repertoire, so Plant got in touch with us and invited the choir to perform with him. Obviously we couldn't say no this offer,” Koch said, adding that they will also sing three Led Zeppelin songs along at the concert.

Robert Plant was the lead vocalist of iconic British band Led Zeppelin. Since 1980, he has had a successful solo career.

The Academic Women’s Choir of the University of Tartu was founded in 1945 by music teacher and conductor Richard Ritsing.