Those Pesky Slash Chords

Slashing through the Confusion over Slash Chords


     First. listen to  the classic Herbie Hancock  "Maiden Voyage" entirely based on Slash Chords ( the easiest way to notate these chords).   The first chord is C/D --- or in more conventional long-hand notation,    D9(sus4, no 5)

In Maiden Voyage, the slash chord describes a simple voicing chord-quality that is most easily described with the slash symbol C/D.   But slashing has a more important function -
      The quality of a chord has a lot to do with how it's voiced, how the notes are laid out, spread out, left out and moved around.  But even more so, it has to do with the choice of note that is on the bottom.  This note defines everything about the chord quality - in fact, many composers of jazz will routinely write a 2 staff lead-sheet just so they can be in control of the bottom note, feeling that a simple chord-symbol is just TOO simplified.  Music notation evolved to allow us to specify that bottom - note, short of actually writing out all of the notes on the staff. We call these chord symbols "slash chords".   Slash chords also specify the exact notes that are to be included with the chord, just not exactly how to play them.

          But there always seems to be some confusion about "slash chords"....   I know this because I never know what note will come from the Bass Player when I give out charts that contain "slash chords".  Back in the 17th Century (and still today!)  music notation made use of "Figured Bass" to be very specific about what note to put on the bottom, or more accurately, what inversion of the chord was to be played.  It is a very important component of composing and arranging. The bottom note progression defines the quality of each chord in the harmonic progression and allows music to be so much more interesting than when it always just has the root on the bottom. The manner in which the bottom note progresses is one aspect of music that brings it to life.


  For example , this Figured-Bass notation on the left describes a Bb triad in 2nd inversion by laboriously describing the intervals that make up the inversion ( a sixth and a fourth ). 

    Nowadays, in the jazz world anyway,  we use the some what less specific and less cumbersome Slash System to at least specify the bottom note, since the bottom note is so important to the sound of the chord and is heard as an important countermelody in its own right. We tend to leave the choice of actual voicing to the player, in jazz and pop music.    As simple as it seems, there is still confusion about the system, however.


The most common form of slash chord is the one on the left - note the diagonal slash to denote the top CHORD,  from the bottom NOTE.   

      One school of thought recognizes a second kind of slash chord ( on the right )  with a HORIZONTAL slash to denote the top CHORD from the bottom CHORD -  a polychord.  This is much less common and I would never assume this notation unless instructed by the arranger.

                               Back to the regular diagonal Slash Chords ---
     Slash chords fall into 3 categories   (examples below use F as the given Low Note)....
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FIRST Category     -  simple inversions of an F triad

    F/F      a type of F chord
      F/A       a type of F chord
    F/C         a type of F chord
     F/Eb               a type of F chord              (F7)


.....    where the bottom note is just one of the chord tones but the root of the chord is still F.
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SECOND Category

  The bottom note is functioning as the ROOT of the chord. Slash notation here is to specify a chord type or voicing in a simple way.  Note that none of these is actually an "F chord" in sound or in function.
   F/G     a type of G chord,                    G11(omit 5)   or G9(sus4, no 5)
   F/Bb     a type of Bb chord                   Bbmaj9(omit3)
    F/Db        a type of Db chord                    Dbmaj7)#5)
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THIRD Category

    Function is up for grabs on these more dissonant chords, completely dependent on context ( of course the F/D you will recognize as a Dm7, not dissonant,  but in certain contexts writing it as a slash chord actually might make some sense). Tonality is ambiguous.


F/Gb    F/Ab   F/B   ( F/D )    F/E
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Here is a schematic of all 12 Slash Chords in the Key of F to visualize the 3 categories described above:

  And I just have to mention -  in writing Slash-Chord symbols correctly, it is often desirable to use a Cb or an Fb  in the chord symbol - particularly  when writing  chords like Fm7(b5)/Cb   or Bbm7/Fb .  I have learned over the years, though, that this is an almost guaranteed way to hear a wrong note coming from the bass.  Please be advised that    Cb is B      and      Fb is E.     Just for the record, because it is just plain illogical to write Fm7(b5)/B and I hate to do it just to increase the probability that the symbol will be read correctly.  
  And for an absolutely guaranteed wrong note I would write  Ebm7(b5)/Bbb - pianists tend to read Double-Flats fairly often in Classical Music but this will trip up Jazz Bass players every time - no disrespect to Jazz Bass players!  


      Now, with that knowledge,  let's look at what scales an improviser of Jazz might play over slash chords - understanding what the chords REALLY are can empower some good soloing...
F/A           F major
F/C           F major
F/Eb         F mixolydian     ( it's an F7)
F/D          D aeolian     ( it's a Dm7 chord, the vi chord in F )
F/G          G mixolydian   ( it's a G7sus chord )
F/Bb          Bb lydian or major      ( it's a Bb chord )
F/Db          Db lydian, #5     ( it's a Db chord    with maj7 and augmented-5th )

... happy slashing.