Sifflait is the imperfect tense of the verb siffler, meaning "to whistle". While seemingly simple, its use here evokes a strong sense of nostalgia and a specific cultural memory.
In the song, the line "Papa nous sifflait, le jour s'embrumait" (Dad would whistle for us, the day would get hazy) paints a vivid picture of childhood evenings. It's a common, yet deeply personal, memory for many French speakers, where a parent's whistle signals it's time to come home, connecting the listener to a universal feeling of home and family.
Terrenoire is a neighbourhood of Saint-Étienne, and this song is the duo's love letter to it, sung from far away. The singer lives in Clichy now ("J'vis toujours à Clichy" [I still live in Clichy]), has stopped counting "le nombre de fille, le nombre de nuits" [the number of girls, the number of nights], and keeps catching himself saying "J'suis pas un gars d'ici" [I'm not a guy from here].
The best part is the middle, where the song turns into a list of place names: "Gamotière, Perrotière / St Jean, St Charles / La Métare, le château". These are spots in and around Terrenoire, recited like a prayer, and the list lands on "La maison, le cimetière" [the house, the cemetery], which is a blunt way to sum up where you come from. Before that he remembers golden hills "par le soleil du soir" [by the evening sun], Dad whistling them home, and dinners eaten "en silence devant la télé" [in silence in front of the TV].
Watch the phrase "mémoire de forme": it means memory foam, the mattress material, so the soul resting on it is a funny, tired image. Also listen for the dropped vowels in J'suis and J'vis, which is how people actually talk.