[Harp-L] Bass harp layout

[Michael Rubin <rubinmichael@xxxxxxxxxxxxx>]

I've recently purchased a bass harp.  It is two harps, on on top of the other.
  The bottom harp is all white notes, two octaves starting on E.  
  The top harp is strange.
  F F# G# A# B C# D# F F# G# A# B C# D#
   
  I understand that F can be considered E#, so that note makes sense.  WHY do they have the note B?  C would make sense, as it is B#.  I suppose B is Cb, but then they should have E instead of F.
   
  The only thought I have is this:  Harmonica bands are fronted by chromatic players.  I think it is fairly common practice for Chromatic players of this style to focus on the key of C.  A common chord would therefore be C7 spelled out C E G Bb.  Three notes played on the bottom harp, one on the top.
   
  A common trick to creating exciting at the end of a song is to raise the song up one half step in key, to the key of C#.  The C#7 chord is C# E# (F) G# B.  All of those notes would therefore be available on the top harp.
   
  This is the only explanation I can find for the layout.  Does anyone else have any ideas?
  Thanks,
Michael Rubin
  Michaelrubinharmonica.com