you really wanna know? haha... we have large number of opened cassette decks and other obsolete technology hanging in the space, with loops going between them. every pair of decks has one recorder and one player, mics in the space pick up the sound for some 'interactivity', if you will. and feedback of course. some decks can be turned on and off by just powering it on and off, since the tape head will stay on the tape when it's a purely mechanic mechanism. so we will switch whole pairs then.
some stand-alone decks, as we call them, have just the control switches hacked, so a single tape will record, play, stop, rewind and fast forward. here we have to switch the functions with single relays. can be done better probably, but we also like the sound of switching relays...
to not have electrocuted visitors, we hang the transformers out of reach and extend the low voltage ac coming from them to the decks at eye level and lower, to show them the beauty of circuitry.
does that answer your question? :-)