Here is the essence of the project in I minute:
If you now want to know about it in a little more detail, here is a 5 minute trailer:
If you'd rather read it, here is a brief description from the creators themselves:
"We wanted to create a project that would bring together as many musicians as we could – an impractical task in the real world but not in the digital world of sampling! So taking recording equipment with us on nearly every gig for 5 years, we filmed hundreds of musicians from countries, amongst many others, Brazil and Mexico to Senegal in West Africa, across Europe, China and Kazakhstan in Asia and even Egypt during the revolution. We then cut up thousands of recorded samples, creating new music, recontextualising musicians as if they played together, when in reality none of them ever met or heard recordings from each other.
No tracks were written beforehand, the samples would dictate the direction in the studio, no musicians played in a pre-defined key, they all just improvised and our creative process was simply to just see which samples worked together. Then afterwards, in some cases, we wrote or collaborated and added lyrics. Orchestra of Samples is an exploration into serendipity and musical probability, it’s about bringing people together who wouldn’t normally perform together, and more to the point their instruments which wouldn’t normally be heard together!"
Find out more:
http://www.orchestraofsamples.com/about/
I saw them a couple of days ago performing an hour long set at WOMAD. Not only the music was brilliant, vibrant and made everyone dance... the performance was simply exhilarating. As the samples were brought in, the little windows on the screen behind the band opened up to reveal the musicians playing, singing, and it felt like they were actually "present". The prerecorded samples were accompanied by some live guitar and percussion on stage. Beyond the masterfully crafted music, the concept itself was just so beautiful and uplifting, you just couldn't help but fall in love with it all.
I've found a really good quality recording of one of their full gigs in Rome, from 2014. (A very subdued audience, if I may say, but at least they don't interfere with the sound.) If you don't have time to listen to it all, you can always just "sample" it,
My favourites:
The introduction and 'Easter Baschet' straight after.
'Sundown (That's a fact)', starting at 17:50
'Beachcoma', starting at 32:39
I have heard of one other group (Timesbold) who does a slightly similar thing with their music on a much smaller scale. The members of the band don't even live in the same town. Ain't technology amazing? Thanks, will come back in this "room" when I have more time.
Must probe further with this band. 
---I do find it a test to work within the confines of the online world, only because I am so curious & enjoying all these new adventures so intensely!!)
