Howdy Djim,

Well, without seeing the entire file, there are a couple of things that could be going on.

1. The file might actually be in C, but have so many "jazz accidentals" (or as a friend of mine says, it might "accidentally be jazz" ;) ), that Composer is interpreting the key as Bb. You can change the key signature just by double-clicking it and using the dialog to change it.

2. The file might actually be in Bb, but be played in a different "mode". Here (a whole step up) it would be Dorian, very popular in Celtic music and some jazz.

Modes give a different "flavor" to a piece by returning to a fundamental that is different than the major key would expect. This concept is easiest to see and hear on a keyboard.

If you play the C scale on the white keys starting at some C and ending at the C an octave up, you get the familiar "do re mi ..." scale. BUT if you start on D ("re") and play up just the white keys to the next D, you're playing all the same note pitches as before, but now you've played them in the Dorian scale, which is a "mode" of C. By returning to the D rather than the C, you've changed the sequence and the fundamental, and it gives it a distinctively different feel than the C major (Ionian mode) scale sequence.

So, that's the short version I'd have to see the whole file to know which it is.

ttfn,
Sherry