Answer to question #1: When BIAB first came out, there were only a handful of built-in styles available (and they are the ones that start with ZZ in the main part of the name). They were lettered "A" through "I don't remember the last letter". So when you saved a songfile that used style "N", the extension was "SGN". If you saved a song with style "B", the extension was "SGB".

Once more styles became available, they started changing over to using "U" (for User style, although at the time, this included new styles created by PGMusic). That's why most BIAB file end in "SGU" now (or "MGU" if there is a melody or soloist track in it). It really is a legacy thing, and there is an option to save all files as "SGU".

John

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