Well...i believe that most of us here have this "musical ear"...or may also called "play by ear talent". Well, should say that I have this talent too...but didnt really realize how did I learn to polish it. Until oneday, I try to remember what have i learned within my 11 years of playing...never thought that I would be crazy at guitar at age 12...I just learn for fun bcoz i saw my father, my uncles and aunties...most of them know how to play guitar. SO i started to learn normal chords like C..Em..F..G..then my uncle taught me a church songs...using on the 6th and 5th string string...from here...i saw my father cathing up chords by just hearing it. I was wondering ...how the hell he knows the chord by just hearing and guessing it? I ask a lot of questions...until I found out that...to have your ear working as a musical instrument...first, u gotta to familiarize yourself to sounds of chords progressions...the bass line progressions...all is by Experience...u heard it...then u knew it was this chord to that chord...or...u listen to this bass line...it is so familiar...maybe it is G...Em...C...D...or.... A...F#m...D....E...its all through experience and dont forget..."Imagination". If you are able to imagine the chords and bass line...then u might be able to guess what is the chords...for cathing up lead scales....of course...u need this imaginations...combine with ur existing knowledge...and dont forget...a good radio or CD to playback clearer sound so that u r sure of the notes. Hmmm...guesss...I am too much sharing...oh well... this is what a forum is used for, right? Hope that helps... ;p