Conversation so far:
What was the approach used to creating Good Vibrations?
Instead of working on whole songs with clear large-scale syntactical structures.
What alternative was used instead of working on a whole song?
Wilson limited himself to recording short interchangeable fragments (or "modules").
Through the method of tape splicing.

Question: Had this approach ever been used before?
Self-contained rewrite: Had Wilson limited himself to recording short interchangeable fragments approach ever been used before?