Q: What is a chromatic harmonica?

A: Extending the discussion of general types in part 1, a chromatic
harmonica is a harmonica that has all 12 notes in an octave directly
available. It is actually tuned in a diatonic scale, but it can be raised a
half step by pushing a button on the side — BB

Also from “Post #2 General Stuff” 2 Nov 1992 JE:

The standard chromatic tuning is different and called “solo” tuning. The
entire scale is repeated in each set of four holes (just like holes 4-7 of a
diatonic). 12 hole chromatics are available in 12 keys. 16 holers are only
available in C. A 16 hole chromatic has four complete C scales, with the C
repeated in every octave. See layout below…

(TOP LETTER = BLOW / BOTTOM LETTER = DRAW)

  1.  2.  3.  4.  1   2   3   4   5   6   7   8   9  10  11  12 <-cover plate #s
  1   2   3   4   5   6   7   8   9  10  11  12  13  14  15  16  - may differ
+--++--++--++--++--++--++--++--++--++--++--++--++--++--++--++--+__ ++
|C#||E#||G#||C#||C#||E#||G#||C#||C#||E#||G#||C#||C#||E#||G#||C#|B ++| (#)sharps
|D#||F#||A#||B#||D#||F#||A#||B#||D#||F#||A#||B#||D#||F#||A#||D |D_/++|<---------
+--++--++--++--++--++--++--++--++--++--++--++--++--++--++--++--+ ++ SLIDE|
+--++--++--++--++--++--++--++--++--++--++--++--++--++--++--++--+__ ++ IN |
|Db||F ||Ab||C ||Db||F ||Ab||C ||Db||F ||Ab||C ||Db||F ||Ab||Db|B ++|<---------
|Eb||Gb||Bb||Db||Eb||Gb||Bb||Db||Eb||Gb||Bb||Db||Eb||Gb||Bb||D |D_/++| (b)flats
+--++--++--++--++--++--++--++--++--++--++--++--++--++--++--++--+ ++
+--++--++--++--++--++--++--++--++--++--++--++--++--++--++--++--+_____ ++
|C ||E ||G ||C ||C ||E ||G ||C ||C ||E ||G ||C ||C ||E ||G ||C |Blow ++| SLIDE
| D|| F|| A|| B|| D|| F|| A|| B|| D|| F|| A|| B|| D|| F|| A|| B|Draw_/++| OUT
+--++--++--++--++--++--++--++--++--++--++--++--++--++--++--++--+ ++ ----->
  1.  2.  3.  4.  1   2   3   4   5   6   7   8   9  10  11  12
  1   2   3   4   5   6   7   8   9  10  11  12  13  14  15  16
 |<- - - - - - - -12 hole layout - - - - - - - >|

Notes:
1. The cover plate numbers on different models/brands of 16 hole harmonica
will differ. Some show the first four holes with a dot beside them to
indicate the octave below middle “C”. Middle “C” is found in hole 5 (the 5th

hole) on a 16 hole chromatic.

2. Hole 16 tuning (slide in) is slightly different from it’s lower octave
companions (1., 5, 9, & 13). Hole 16 contains a “D” note where you might
expect a D# (Eb). Why? I don’t know. (hope these drawings got through the
mail OK.) — “Post #2 General Stuff” 2 Nov 1992 JE