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Bass Systems found on Piano and Chromatic Button Accordions
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STRADELLA - the "standard" on most accordions, with the 120-button
keyboard being the most common.  Many other folks have descriptive
pages on this keyboard, so I won't go into detail.  Check out
Hans Palm's and Jeroen Nijhof's pages for great explanations.

In short, here's the layout of rows.  They differ slightly based on
the country of manufacture:

  Italian
     counterbasses basses+maj3
     basses (circle of fifths, to chin: cgdae..., to feet: cfb-e-a-...)
     maj (1 3 5)
     min (1 -3 5)
     7th (1 3 -7)
     dim (1 -3 -6)

  French
     counterbasses basses+maj3
     basses (circle of fifths, to chin: cgdae..., to feet: cfb-e-a-...))
     maj (1 3 5)
     min (1 -3 5)
     dim (3 5 -7)

  Belgian
     counterbasses basses+min3
     counterbasses basses+maj3
     basses (circle of fifths, to chin: cfb-e-a-..., to feet: cgdae...))
     maj (1 3 5)
     min (1 -3 5)
     dim (3 5 -7) ??

The button layout of the Italian and French keyboards is in
sloped diagonal rows:

  * * * * * * * * *
   * * * * * * * * *
    * * * * * * * * *
     * * * * * * * * *
      * * * * * * * * *
       * * * * * * * * *   top>>>
          outside
            vvv

The Belgian physical button layout is a bit different, though:

  * * * * * * * * * * * * * * * * * *
  * * * * * * * * * * * * * * * * * *
  * * * * * * * * * * * * * * * * * *
    * * * * * * * * * * * * * * * * * *
    * * * * * * * * * * * * * * * * * *
    * * * * * * * * * * * * * * * * * *   top>>>
        outside
          vvv

I've never played the Belgian layout, so it's not clear whether the
chords for a given bass note are directly under the bass button, or
whether they're shifted over one row.  I suspect the latter, since it
would be difficult to finger otherwise.

stradella-120.gif
A standard 120-button stradella bass, Italian-style.
(Originally from Hans Palm's accordion pages:
http://www.accordionpage.com/mb.html.)

stradella-72.gif
A standard 72-button stradella bass, Italian-style.
(Originally from Jeroen Nijhof's accordion pages:
http://www.accordionlinks.com/play.cfm)

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BASSETTI - a "free bass" system (single note per button) using the B
or C system layout as found on Chromatic Button Accordions.  They
occur in two possible arrangements:

  low notes closer to the ground (found mostly on Russian B system
  CBA's called Bayans)

  low notes closer to the player's chin

bassetti.jpg
Free bass system keyboard layout.  Depending on which way you view
this, it could either be seen as either B or C system.  That is, if
the bellows are above the "1st Row," you've got a B-system keyboard
where the low notes are near the floor and the high notes are near
your chin.  If the bellows are above the "3rd Row," you've got a
C-system keyboard where the low notes are near your chin and the
high notes are near the floor.  (Originally from Joe Macerollo's
web site: http://www.joemacerollo.com/bassetti.html.)

bassetti-and-stradella.gif
A 120-bass Stradella layout with three rows of bassetti.  The
bassetti pictured are a C-system layout with low notes near your
chin and high notes near the floor.  (Originally from Hans Palm's
accordion pages: http://www.accordionpage.com/mb.html.)

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QUINT or GALLA-RINI or GALLARINI - another "free bass" system based on
the bass and counter-bass rows of the Stradella system.  On a six-row
quint bass, the top two rows are exactly the same as a standard
Stradella bass.  The middle two rows are the same layout of pitches as
the first two rows, but sounding an octave higher.  The last two rows
again share the same layout as the first row, but sound two octaves
higher than the pitches in the first row.  (Thanks to Doug Creighton
at the Button Box -- he originally described this system in passing
and got me interested.)  To explain the layout another way, it gives
you several rows of basses and counter-basses, stradella style, with
each pair of rows going up an octave.

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HAYDEN - another "free bass" system created by Brian Hayden in the
1960's.  There's a nice interview with Brian available at the
concertina.net site.  The article, and the site itself,
are well worth spending some time on.

hayden.gif A 34-button Hayden system
free-bass, constructed by Rich Morse (r-morse at comcast.net).
(Originally from Terry Knight's keyboard layout pages:
http://www.pied-crow.com/acrd_003.htm.)

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Bass Systems on Diatonic Button Accordions
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This is work in progress.  Check diagrams in the diatonic accordions
directory in the mean time, or the following other pages on this topic:

  Han Speek's page (local copy)
  Chris Moran's page



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Last modified 8 Dec 2002; Noel Cragg