Czech singer-songwriter Marek Ztracený will perform the biggest concert of his career at Prague’s Letná Plain on Friday, with more than 70,000 people expected to attend. The show begins at 8 pm, following an opening performance by singer Martina Pártlová. Ztracený will become the first Czech musician to headline a concert at Letná, which previously hosted Michael Jackson and The Rolling Stones. Organisers are preparing water sprays and medical services because of the expected hot weather, while Prague public transport will provide additional tram and metro services.