I think I know where Mbo is coming from here.....I don't do lyrics, but I have a million billion "snatches" in my head, at least of the chorus, that I could "DO" with the sheet music in front of me because I have heard it so many times, I know where the melody goes,and what the timing does. I CANNOT reproduce these melodies in any kind of format, but I can play the "snatches"...does that make sense?

Extreme example: (for me)-- a lot of the Beatles' stuff....I can hear "When I'm 64", but could not DO it alone. I could probably "fake" around most of it if someone else were leading.

Another case in point--The DT Tune Search Team is looking for the tune to "(The Sinking of the) Reuben James".....this is a Woody Guthrie song that I can hear in my head, and all the search sources say it is to the tune of Wildwood Flower. It is very close, but not exactly a cigar. I could PLAY Reuben James, but I cannot for the life of me notate it.