Belgium was represented at the Eurovision Song Contest 1970 with the song "Viens l'oublier", written and performed by Jean Vallée. The Belgian participating broadcaster, Walloon Radio-Télévision Belge (RTB), selected its entry through a national final.
Chansons Euro '70 consisted of nine shows; six quarter-finals, two semi-finals, and a final. In each quarter-final there were six songs where the top two qualified for the semi-finals. Each semi-final had six songs where the top three qualified to the final, which would then have six songs. All shows were hosted by Claude Delacroix.[1]
Chansons Euro '70 also went by an alternative name in Walloon newspapers: 09.36.70. The numbers represented the number of shows in the national final, the total number of songs competing, and the year. The name would change as the national final went on, and instead represented the number of shows left, the number of songs still left in the competition, and the year.[2]
The qualifiers in the quarter-finals were decided by a jury and postcard voting. The song that scored the highest with the juries and the song that scored the highest with the public postcard voting, as long as it hadn't already qualified with the juries, would qualify to the semi-finals. The jury consisted of 100 people across 10 cities in Belgium who would be phoned and asked to vote for 1 song. Since the postcard voting started after the semi-final had already taken place and the jury qualifier was already known, the jury winner would often place last in the postcard voting.[1]
The jury points for Quarter-final 5 are unknown.[1]
The qualifiers in the semi-finals were decided by two different juries and a public postcard vote. The first jury (Jury A) consisted of 100 people across 10 cities in Belgium who would be phoned and asked to vote for 1 song. The second jury (Jury B) consisted of 100 young people who each voted for a song. Jury A and Jury B voted simultaneously but since the postcard voting started after the semi-final had already taken place and the jury qualifiers were already known, the jury qualifiers would often place low in the public vote. The winner of each jury and public vote qualified; Jury A's qualifier was decided first, then Jury B then the public.[1]
Serge & Christine Ghisoland and Andrée Simons, who had each qualified two songs for the final, both decided in advance to withdraw one of their songs ("Nous serons toi et moi" and "Perle d'étoile" respectively) in order not to risk splitting their vote, leaving only four songs in the final. The winning song was chosen by a combination of two juries: Jury A consisted of 600 TV viewers from 6 cities who were gathered in Dinant, and Jury B consisted of one jury from each of the other eleven participating countries in Eurovision 1970 and several journalists.[1][3]
On the night of the final Vallée performed 5th in the running order, following Yugoslavia and preceding France. At the close of voting "Viens l'oublier" had received 5 points (3 from France and 1 apiece from Ireland and Luxembourg), placing Belgium joint 8th (with Italy and Monaco) of the 12 entries. The Belgian jury awarded 9 of its 10 points to contest winners Ireland, the highest ever mark given by one country to another under the 10-points-per-jury system.[4]