Bill Putnam is a legend in the recording industry. He built studios, fathered legendary gear (the 1176 compressor, among others) and mentored other recording legends (such as Bruce Swedien who recorded Michael Jackson’s Thriller).
I came across this very interesting historical document, typed on a good old typewriter by Bill Putnam in 1980. In it he explains the evolution of recording studios from the 40s to the 70s.
It is both kwaint and modern. Have a read!