Alvin Lucier; I am sitting in a room (Original 1969) by White Devil Productions

"I AM SITTING IN A ROOM"
for voice and electromagnetic tape (1969)

Necessary Equipment:
one microphone, two tape recorders, amplifier and one loudspeaker.

Choose a room the musical qualities of which you would like to evoke.
Attach the microphone to the input of the tape recorder #1.
To the output of the tape recorder #2 attach the amplifier and loudspeaker.
Use the following text or any other text of ant length:

"I am sitting in a room different from the one you are in now.
I am recording the sound of my speaking voice and I am going to play it back into the room again and again until the resonant frequencies of the room reinforce themselves so that any semblance of my speech, with perhaps the exception of the rhythm, is destroyed.
What you will hear, then, are the natural resonant frequencies of the room articulated by speech.
I regard this activity not so much as a demonstration of a physical fact, but more as a way to smooth out any irregularities my speech might have."

Record your voice on tape through the microphone attached to tape recorder #1.
Rewind the tape to its beginning, transfer it to tape recorder #2, play it back into the room through the loudspeaker and record a second generation of the original recorded statement through the microphone attached to tape recorder #1.
Rewind the second generation to its beginning and splice it onto the end of the original recorded statement on tape recorder #2.
Play the second generation only back into the room through the loudspeaker and record a third generation of the original recorded statement through the microphone attached to tape recorder #1.
Continue this process through many generations.
All the generations spliced together in chronological order make a tape composition the length of which is determined by the length of the original statement and the number of the generations recorded.
Make versions in which one recorded statement is recycled through many rooms.
Make versions using one or more speakers of different languages in different rooms.
Make versions in which, for each generation, the microphone is moved to different parts of the room or rooms.
Make versions that can be performed in real time.