(or one of the national languages) of the country being represented. However, they can also have a few lines in a different language. The same rule was in the adults' contest from 1966 to 1972 and again from 1977 to 1998. This rule was later changed so that up to 25% of a song could be in a different language, usually English. This rule was changed again in 2017, now allowing up to 40% to be in English. Originally the competition was open to children between the ages of 8 and 15, however in 2007 the age range was narrowed so that only children aged 10 to 15 on the day of the contest were allowed to enter. In 2016 the age range was changed again. From now on children aged 9 to 14 on the day of the contest are allowed to enter. The song submitted into the contest cannot have previously been released commercially and must last 3 minutes at most. The rule stating that performers also must not have previously released music commercially was active from 2003 to 2006. This rule was dropped in 2007 thus allowing already experienced singers and bands in the competition. As a result, NRK chose to withdraw from the contest. Since 2008, adults have been allowed to assist in the writing of entries. Previously, all writers had to be aged 10 to 15. Organisation The contest is produced each year by the European Broadcasting Union (EBU). The original executive supervisor of the contest was Svante Stockselius who also headed the Steering Group that decides on the rules of the contest, which broadcaster hosts the next contest and oversees the entire production of each programme. In 2011, he was succeeded by Sietse Bakker. In 2013, Vladislav Yakovlev took over the position. Yakovlev was dismissed without any clear reason after three contests, and was replaced by Jon Ola Sand, who had been Executive Supervisor for the Eurovision Song Contest since . On 30 September 2019, Sand announced his intention to step down as Executive Supervisor and Head of Live Events after the Eurovision Song Contest 2020, which was later cancelled due to the COVID-19 pandemic. Martin Österdahl was named his successor, starting with the 2020 contest. Steering Group meetings tend to include the Heads of Delegation whose principal job is to liaise between the EBU and the broadcaster they represent. It is also their