The setting for this all-day indie music party is two unique and gorgeous locations – a horse track during the day and the famous Stahlwerk night club after the sun sets – but most importantly, the annual Open Source Festival (OSF) attracts thousands of club music fans every year.  The top-notch program features international DJs, bands, opportunities to learn about the latest tracks and mixing skills – and of course dancing from the afternoon to the wee hours.  Add to this Düsseldorf’s heritage of art and pop culture (one of the genre’s pioneers, the group Kraftwerk, was founded here in the late 1960s and introduced the new sound of synthesizers, drum machines, and robot-like voices to the world’s dance floors), and it’s the magic formula for OSF as one of Europe’s most important underground music festivals.The party begins at 1pm at the horse track in Düsseldorf’s Grafenberg district on three separate stages, and moves indoors at 10 pm, to the Stahlwerk (steel works) nightclub in Düsseldorf’s hip Flingern district, with many revelers stopping at the historic Old Town, also known as the “longest bar in the world.”  Free shuttle service is provided to connect the venues and keep the party as seamless as possible. US performers “Dinosaur Jr” and “Yasiin Bey aka MOS DEF feat. Robert GLASPER EXPERIMENT” are confirmed as headliners during the time at the race court.  Yasiin Bey is a big name both on the dance floor and as an actor in over 30 films and TV series. “Mala in Cuba” and “Darkstar” (UK) and Jacco Garnder (Netherlands) are also among the day’s performers.  “Modeselektor” from Berlin and Düsseldorf’s local stars “Kreidler” and “AI” will continue the dance beats after sunset at Stahlwerk.Day-only tickets (€32) and a limited number of day and night tickets (€42) are available. For more information about OSF and tickets, visit www.open-source-festival.de.The city’s tourism office is offering hotel and city specials for many of the city’s music and art-related events throughout 2013, including OSF 2013.  The hotel package called “Open Source Festival” can be booked right from the tourism office’s website at www.duesseldorf-tourismus.de/osf.  Prices start at €49 per night per person based on double-occupancy for a 2-3 star hotel in the city center and at €95 per person for a 4-5 star hotel.  All packages include breakfast, a Düsseldorf Welcome Card (free public transportation within city limits, plus more than 40 free or reduced admissions to city attractions), a city information package, and a MERIAN city guide.