On compression, the early (analogue, tube) tape recorders would saturate the tape, typically about 14dB above the maximum VU-meter level. (The VU meter does some short-term averaging so it reflects the perceived loudness but not the instantaneous peaks.)
A little later, compressors were developed to do a smoother job - especially useful for radio broadcasts which exhibit hard clipping. Gradually over the years better compressors were developed so that the perceived loudness came closer and closer to the instantaneous peak level, allowing radio stations to play music that sounded louder and thus appeared to increase the distance range of the station without increasing transmitter power. Also, the louder-sounding station was more attractive to listeners spinning the know across the dial. This gradual slide into mediocrity has continued to this day - that 14dB is now about 1.5dB for much of pop music. :^(
