To accompany the visual art of Laure Catugier I performed two long sound improvisations in the basement of ReTramp gallery. For the opening I stayed underground for 3 hours and for the closing 1.5 hours. The gallery visitors did not see me in person during the opening and only as a small black and white projection for the closing. The sound was meant to invoke the underlying pulse of a large city, with deep bass and harsh screeching peaks. Two large speakers ensured that the floor of the gallery vibrated under the feet of the audience.