This was on a fabric computer keyboard made into a gigbag. Or a gigbag made into a computer keyboard. Could be woven into a shirt. Which means that a midi keyboard could be sewed into your sleeve? The link to the developer is at the bottom. (Actually, I'm not sure I understand the basic function of this: you need a laptop to plug this in to. And the laptop would have it's own keyboard, yes? )

Smart Fabrics and Mobile Musicians

Posted by Jason "The Puppeteer" Fewings
UK Smart Fabrics developer Eleksen have designed a carry bag for your laptop, or mobile computer that doubles as a fully functional wired (or bluetooth) computer keyboard. With smart fabric sensors integrated into the fabric of the keyboard, these durable and washable bags make it easy to be mobile. Simply take your computer out of the bag, hook it up and to the bag and start typing.
The smart fabric technology can apparently be embedded into all manner of synthetic and natural fibers, including custom designs, making it possible to actually wear your logic key commands or your Ableton Live Clip Triggers. Elekson claim that the fabrics and sensors are extremely durable even surviving being run over by a car (though we don’t think that this is something you’d like to test while actually wearing smart fabrics. They may well be durable, but I doubt it will make you any more resilient to fast moving vehicles!)
More information can be found at Eleksen’s Website.