[jhallenworld]

Reel to reel at 7 ips was quite good. I remember my dad's Akai player from the 50s even supported quadraphonic. Too bad this isn't catching on..

[ams6110]

There used to be some specialty cassette decks that would record 4 track audio on a cassette (it used the full width of the tape rendering it one-sided). Used often for demos, or low-budget studio work, etc.