The Ritual
It must be conducted under the sky on a starry night. Attempting it on a rooftop in a city clogged with light pollution imposes a -10% penalty to the activation roll. The operator plays an atonal melody on a wind instrument, though no Art skill is needed. It's like a musical form of automatic writing. Most versions of the ritual include sheet music or instructions for writing your own. Part of learning the ritual is understanding that while great skill is required manipulate Azathoth's dreams, it is also completely irrelevant, as everything is destroyed as it comes in contact with His maelstrom of creation.