Current methods of producing stretch vary in how precise they are in describing just exactly what the piano technician must do to consistently get the best sounding stretch on a piano.
Vague instructions, or telling beginners they just need to tune 1,000 pianos before they “get it”, is not very helpful.
Even though one must spend many hours actually tuning in order to master this skill, it helps to have a specific procedure described that produces consistent stretch that sounds beautiful.
The Go A.P.E. Aural Piano Tuning Stretch Procedure does just that.