The Singing Tesla Coils are two custom engineered Tesla Coils that generate electrical arcs (1/2 million volts) that act as an instrument producing a sound similar to that of an old synthesizer. Accompanying members of the Tesla Coil band include a robotic drum set and other live instruments performed by creators of the Tesla Coils.
Students from the University of Quebec put together this one take music video earlier this semester. It involved 172 performers and took about a month to plan. They only did two full runs. This was the second.
The sounds you are hearing are from the Portsmouth Sinfonia.
The Portsmouth Sinfonia was a real orchestra founded by a group of students at Portsmouth School of Art in Portsmouth, England, in 1970 — however, the Sinfonia had an unusual entrance requirement. Players had to be either non-musicians, or if a musician, play an instrument that was entirely new to them. Among the founding members was one of their teachers, English composer Gavin Bryars. The orchestra started as a one-off, tongue-in-cheek performance art ensemble but became a cultural phenomenon over the following ten years, with concerts, record albums, a film and a hit single. They last performed publicly in 1979. [wikipedia]