Some failed experiments in audio technology, including the head-mounted turntable and the oxygen-free listening room.
If oxygen-free copper is a good thing, then clearly oxygen is a bad thing for audio. The largest quantity of oxygen the sound is likely to encounter is in its passage through the air from loudspeakers to listeners. The only way to address this is: The Oxygen-Free Listening Room, which is filled with pure nitrogen.
(Joking aside, some of the speakers in project #10 now make up an art exhibit with a message.)