It's true. By the end of
the 1980's, the major
record labels had every element of the
pop "formula" filed away in their
archives. After reaching a covert agreement with the recording artists
unions, there began a systematic
decommissioning of human acts from the singles chart. It takes teams of highly trained
engineers to perfect the illusion that the bands in the modern Top 40 are real.
They have many tools at their disposal : sampling, session musicians (now more or less phased out), genetic algorithms, statistical analysis of sales figures matched to characteristics of the waveforms of tens of thousands of songs. Live appearances are generally staged in an aircraft hangar with the artists and crowd digitally manipulated to suit the executives' aims (for instance the addition of Pepsi logos to every available surface, and the erasing of unsightly audience members).
Some acts are a kind of "in-joke" between the (now retired) artists and the engineers. For instance Sean "Puffy" Combes (a heavily tweaked version of the MC Hammer model, incorporating procedural texturing to render his ridiculous fur coats) was designed to amuse Sting. Jennifer Lopez was put together by Pixar. Ronan Keating (a kind of replicant built from the DNA of Terry Wogan, with the mind of a gibbon) was an early experiment in boyband cell division (as explained by RalphyK here). Countless other "musicians" are built by picking and mixing elements of past performers and adding new, media-friendly twists.
More information about this Illuminati plot will be posted as I find it...