I would like to better understand the "natural arrangement" option. The manual says, "If you give a pro musician a complicated chord progression with fancy extensions like C7b9b13 or Gm11, the musician may reinterpret these rather than playing them exactly as written. This can achieve a much better sounding arrangement because the musician has freedom to choose from similar chord extensions. You can get Band-in-a-Box to do the same thing with this option for all tracks in all songs." Apparently, there is a natural arrangement process by which complex chords are simplified. But there are multiple ways of simplifying chords, with very different results. For example, the C7b9b13 and Gm11 chords mentioned in the manual could be simplified to C7 and Gm7, respectively. A good musician is not like to make such substitutions. Better simplifications would be those which omit the root (left open for the bass), but preserve the interesting color of the specified "fancy extensions". For these chords we might have the substitutions Bbm7-5/C and BbMaj9/G, respectively, with the C and G notes omitted to leave room for the bass. To make best use of the "natural arrangement" option, users need to know exactly what Band-in-a-Box will do to simplify the chords in an arrangement. Is there a list of "natural arrangement'" substitutions that Band-in-a-Box uses, or a process it uses to decide what those substitutions should be?