If you set up a diatonic for just one key it would. But you can have a diatonic like this one I have:

G9 D4 D6/9 A4 A6/9
Emin D*7 Bmin C#dim F#min

G A7 D E#7 A

with the strings tuned gadef#gabc#ddeef#f#ggaabbc#c#ddeef#f#ggaabc#dd

and there you have two keys with some limitations.

The f#7 and the E7 are [partial chords with no third. the 9th are added- no 7ths. 4 means suspended 4th

The D maj scale would be def#gabc#d

The key chords (triads) are D Emin F#min G A Bmin C#dim D

The D6/9+ chord =D major pentatonic scale= d, e, f#, a, b

and by pressing two chord buttons you get the following drones:
D drone g9 +d or D4+ D
E drone Emin + E7 or Emin +D6/9

F# drone F#7 + Fmin
A drone D69 + A or A4 + A
B drone Bmin + A6/9

hope I haven't confused you...hg