Runrig's song "Fichead Bliadhna", too, but that's more kind of a protest song:

Ruith sa mhonadh, ruith nam beann

’S mar sin dhan sgoil aig deireadh samhraidh

Nar clann aig còig bliadhna dh’aois

’S gun facal Beurla nar ceann

translated:

Freedom of the moor, freedom of the hills (Ruith is literally "running" though)

And off to school at summer's end

As children of five years old

And not a word of English in our heads

Particularly resonant with me as my 6-year-old cycles off to school for the second month of Primary 2. Quite a wrench to have to deal with sitting still and listening to the teacher when it's 20° outside and sunny and there are bikes and toy cars and mud and sticks.

At least some twenty years later by the late 70s when I was that age they actually were teaching Gaelic in schools again instead of literally beating it out of people, and now my son is in a Gaelic-medium class in school making it one of the three languages he speaks.