That envelope is the conceit around which the video for "Sing" by The Dresden Dolls (from their album Yes, Virginia...) is built.
The fantastic in this video unfolds very subtly, and includes the vignettes of the envelopes and their recipients, and the tableau vivant of living statues with which it opens. The envelopes go, it seems, to people who need them - by post, by hand-delivery, by some strange and sympathetic magic. As the song builds, we watch as their recipients open them, read the card, place the CD into something that will allow them to hear its contents. They begin as people in various states of being visibly broken, and as they hear the music, as they sing, they are healed.
These scenes are intercut with scenes of the Dresden Dolls (Amanda Palmer and Brian Viglione) performing the song in a condemned theatre, with an audience of living statues. The song affects the statues - they move out of their tableau, and regroup themselves ever closer to Amanda and Brian as if drawn by the power of the song.
The song, and the accompanying video, are an amazing meditation on the power of art. In the scenes with the statues, we see the idea of art as performance - they are in a theatre, and while the audience may be statues, they are performers as well. In the scenes with the recipients of the envelopes, we see art in the world, and the argument that it can change people who choose to participate in it. Who choose to respond to terror, and grief, and the pain that are far too often a part of life with an act of creation. Who sing.