The 1st season featured Toccata and Mordicus, as well as a cast of four adults (Roger, Odile, Clémence and Maxime) and two children, Fabienne and Rodrigue.
Each of the characters (except for Odile who had a leitmotif and the two aforementioned children) had their own signature song, along with two duets (by Toccata/Mordicus and Roger/Clémence) and an occasional closing "street anthem" sung by the entire cast.
Afterwards, a new set of segments, known as "Des yeux pour voir", would either feature Toccata or Mordicus or both characters venturing outside of their normal terrain and engaging in various activities.
These segments would be filmed on-location instead of taped, and the duo were rarely accompanied by the other street characters, usually Roger and Trepido.
Sometimes, an additional filmed segment would appear as a short "Gag", while "Des yeux pour voir" and the street scenes would be switched occasionally.