This is a bit of a cheesy song, but has a great message and uses the imparfait. I love using music in French class with fill in the blank activities. I sometimes will create worksheets with different levels (more or less blanks) or more front-loaded vocabulary before listening to the song.
I would use this after having looked at the imparfait for a few classes or as a review a year later.
As a follow-up, you could have the class translate the song in groups/pairs.
Other grammatical concepts to explore: indirect object pronouns, direct object pronouns
Vocabulary: lexical fields pertaining to sight and the bakery.