Changes are also being introduced to both the voting system and the format of the live shows.
The Eurovision Song Contest is organized by the European Broadcasting Union, the alliance of European pubcasters.
Fans have speculated that ABBA might appear in virtual form as they do in theABBA Voyageconcerts in London.
Eurovision rehearsals are underwayJens Büttner/picture alliance via Getty Images
That show uses motion capture to create digital avatars of the band.
Eurovision topper Osterdahl said getting viewers more deeply involved was another key goal.
Were always trying to tweak this format, he said.
They still automatically have a place in the final.
The same is true of Sweden as host country.
This has happened twice before, but not since 2011. International Eurovision fans can vote even earlier.
The semis take place on May 7 and 9.
The final is on May 11.
