To Mac and Eddie, unless you both were prodigies, that ability took you years of woodshedding where you had the chords in front of you or someone calling out the chords or telling you the structure as you were playing. Doctors aren't born, they learn over time. If this analogy of the doctor was reasonable then disdain should be cast down upon every fake book touted here as well. Or any chord chart ever used before figuring out the chords by oneself, etc. if it were reliable, which one day this will happen, it will be a great learning tool to develop the ear to identify chords on audition only. There are plenty of university type folks working on automated score generation. An acquaintance of mine, Dr. Gregory Wakefield at U-M (sorry Eddie) usually has at least one PhD candidate working some new angle of this kind of topic in his Computer Science program. Greg is an accomplished singer as well as computer algorithm and DSP wizard.