The entire ceiling area was faced with acoustically absorbent material.
Good sight lines are important acoustically as they prevent absorption of the direct sound by grazing incidence over the heads of the audience.
The floor is a wire trampoline stretched between the walls with an acoustically transparent catch net below.
However, not many people realize that many of Nirvana's songs either use an acoustic guitar or can be played acoustically.
Following a performance on MTV Unplugged (a popular show where bands would play their songs acoustically), the band's acoustic reputation began to grow just as the band itself began to disintegrate.