These are short videos made by people in offices, lip-synching to pop and rock songs. It has to involve a group and appear spontaneous and most of them are made in one bravura continuous take.
Lip dubs have been made by schools and families. Even a movie star or two get into the act:
I love the creativity and spirit and I especially love the way you get a sense of these different office environments. Makes me wish I was still a Cub Scout Den Mother — we would be all over this!