Today is anniversary of Eurovision Song Contest 1957. 58 years before Frankfurt hosted the contest and The Netherlands won first time… Großer Sendesaal des hessischen Rundfunks hosted the and presenter was Anaïd Iplicjian.
10 countries (Belgium, Luxembourg,UK, Italy, Austria, The Netherlands, Germany, France, Denmark, Switzerland) were in second edition of the Eurovision Song Contest. Austria, UK and Denmark entered the contest first time.
Two artists who had participated in 1956. Corry Brokken for Netherlands; and first winner of the contest who is Lys Assia for Switzerland.
After competition The Netherlands won the contest Corry Brokken ‘s song “Net als toen” (Just like then).
Danish entry was sang by Birthe Wilke and Gustav Winckler. The couple gave viewers the longest on-stage kiss in the history of the contest to date. 
“The participating countries were represented by one song each, but the duration of the songs varied. The UK entry lasted for only 1:52 minutes, whereas the Italian lasted for 5:09 minutes. Even though the rules suggested that a song should not exceed three minutes, the Italian entry was not disqualified despite heavy protests. The incident lead to the restriction of each song to last a maximum of three minutes. Another change was that the national juries could not vote for their own song anymore, a rule that still applies today.”-eurovision.tv
Winner: Corry Brokken – Net als toen
https://www.youtube.com/watch?v=ms6Huhv19AQ
You can watch full show of Eurovision Song Contest 1957:
https://www.youtube.com/watch?v=eFQRREsVn_Q