doing the record collection math

Ethan's 1973-1990 survey is insane. The record descriptions are generally short, but any blogger will appreciate how much work it takes to draw up a list like that one. Ostensibly, he's patching together a history long past, but my favourite aspect of it is that in the cracks there emerges an idealised community of present-day jazz musicians listening to bootlegs, copying the masters' solos or playing on their recording sessions, then having lunch. I am mildly worried by how few of these records (nine) I have.