Well this sounds intriguing:

“A monthly workshop for exploring acoustics and building musical instruments of all kinds. Held in London Hackspace, join us on the journey and pick up a few hands-on skills along the way! The group is still in it’s infancy and we’re learning as we go, so if you have any expertise and would like to do a demonstration, run a workshop or simply come along and share your knowledge, please don’t hesitate to contact us.”

More info at http://acousticlondon.tumblr.com/
Next meeting on Sunday 257 May 2014 at London Hackspace https://london.hackspace.org.uk/

You might also like the Music Hackspace http://musichackspace.org/