Repetition and the Ear That Won’t Sit Still
Repetition can produce difference without adding an event to a recording.
Put a short loop on repeat and there may come a point at which you hear an event you were hearing as accompaniment become the start of the phrase. The recording has not been given a new entrance. The distribution of attention has changed. An arrangement can give a listener enough time to have this experience and prepare something else to meet it when it happens. Very little of the work requires that the listener always give the same account of the pattern.
Sometimes the more a pattern repeats, the more precisely one can hear where its attacks want to group. A repeated chord might initially resemble a background with equal weights. A bass articulation later makes one of the supposedly ordinary spaces feel like a turn. When the bass part goes away, the chord may keep the shape the bass gave it. There is a musical event in the interval between withdrawing the cause and the listener letting go of the impression.
The risk of remaining still
A composer can ask for attention in this way and fail to supply an object with enough internal relations. The listener may have exhausted the possibilities they were able to hear. Repetition can also expose a weak sound whose first appearance benefited from novelty. I feel no obligation to take the passage of time as evidence of daring. An extended piece has to bear the possibility that somebody understood what it offered and believed they had heard enough.
Successful music need not concern itself with producing novel sensations on every pass. A refrain can remain meaningful because it gives the listener a dependable sensation at several points in a piece whose other relations are becoming difficult to follow. Other parts can take a greater risk because the refrain has been willing to stay recognisable. Repetition can be a source of security and make it possible to go farther away. Its work depends on where that secure point came from and what has changed around it.
A repeating piece gives the listener somewhere to stand while matters in their own hearing become less settled. Occasionally the same sound makes two incompatible things available within a short time. I would like descriptions of musical development to reach that experience. A person can finish a work and report very little change in the recorded material. The reason it mattered to them may be that they heard it differently toward the end and could not work out how to go back.