Hi you guys,

Well, it does look like it's basically in C, since the majority of chords are built around the I, IV and V chords of C, although there are those that it takes a somewhat tortured analysis to make come out that way. The ending provides a good example. The final chord is a C with a minor 7th and 9th, the 5th missing. Just before that you could say it's a Db chord with the same basic structure, but you could also say, I guess that it's an augmented F chord with a diminished 4th and minor 7th. The important thing is that, for me, it makes a nice indefinite cadence. In a number of places, I'd just call some of the chords combined, such as in measure 11, where a G major and G minor are combined. If you look at just the notes of the melody line, you see pretty much a piece in C.

I don't see any inescapable logic to the key signature, and wonder if perhaps it was assigned to reduce the number of accidentals to a minimum, which would make sense.

What my ear sends to my brain results in hearing a catchy enjoyable piece. So if Jaco just plays the notes that he sees, it should sound good. And it may be more fun in sunny Portugal than usually overcast Southeast Ohio.

all best,
mgj