The growth of popularity of sliced cheese was the result of an act of kindness by an eccentric philanthrophe named Wallace - he bought up all the unwanted banjos, and installed them in a factory, busily mandolining (!!!) cheese around the clock. His friend Gromit said it was all doomed to failure.

And it was - because of the sudden removal of such a large number of instruments, makers foolishly began rapid manufacture to replace the supply, as it was erroneously thought that the instrument was experiencing a re-surge in popularity!