Recommend some great rockumentaries

I'd like my kids to understand Spinal Tap when they watch it[1]. I suppose they should have seen an example of what's being satirised before seeing the satire. What should they watch first?

The analogy in my mind (accurate or not...) is to watch Bond before Austin Powers.

[1] Basically I want to make dad jokes about exploding drummers and get groans rather than mystified looks.