My uni housemate had a stereo that did all kinds of interesting stuff
One of its features was that your could enter your date of birth, the stereo would calculate your "biorhythm" and then suggest a genre of music you might enjoy from one of its speaker presets like Rock, Jazz, Pop, Folk or Soul. I rather liked it as it reminded me of Dirk Gently's I Ching calculator.

Of course, to get the best out of it you also had to own at least one CD from each of the above genres...
( emvee cruor deo cruoris, Mon 3 Oct 2011, 10:44, 2 replies)

it wasn't an Aiwa by any chance? They were packed with utterly useless features like that
Mine had a sort of tombola game that used to play while it was in standby. Three numbers would spin and you had to press the button to stop them in a sequence (3,3,3 or something) The game was completely rigged though as every 10th spin would always take a few seconds longer as it correctly lined up the winning numbers.
( h3donist tryin' to play me out as if my name is Sega.., Mon 3 Oct 2011, 11:36, closed)

I think it was Danny Baker
that said he took an AIWA apart once to see what the 'Noise Reduction' button did because it didn't make any difference that he could tell and it turned out that it was literally just connected to a red bulb.
( scarpe We Stole Bikes, Mon 3 Oct 2011, 11:40, closed)