Final answer:
The question pertains to a song that underwent a technical process involving four reduction mixes in music recording, with the final mix recorded onto an open track of an earlier tape.
Step-by-step explanation:
The question seems to be referring to a specific song production technique in the field of music recording. The technique involves using reduction mixes, a process where multiple tracks are combined (reduced) into fewer tracks to free up additional tracks for further recording.
In traditional tape-based recording, this was commonly done because of the limited number of tracks available on the recording medium. The song in question would then have undergone four reduction mixes before the final mix was recorded onto an open track of an earlier tape to complete the process.