I created a fairly random sequence of sixteen notes using Beepbox and this was repeated sixteen times with a note removed each time until the last repeat is silent. The result of this process was played with a drone backdrop which, needless to say, gradually takes over as the piece progresses. A little reverb etc was added at various stages.
More on the 728th weekly Disquiet Junto project, Note Down — The Assignment: Delete a note at a time — at https://disquiet.com/0728/.