My Swan 1248 chromatic was tuned to A=440
(the pitch A, in the treble clef, vibrates at 440
cycles per second).
A=440 is an international tuning, set to make musical
groups world-wide, in tune collectively. In the past 50
years or so, that standard has been changed by individual
performers and small groups.
On the harmonica, the manufacturers have stated that
when a performer plays, the pitch is brought down a
few "cents". If the pitch starts at A=440, it will drop
to A=438, etc.
So, the manufacturers have set the standard tuning to
A=442 or 443, and the pitch goes down to A=440.
That doesn't always work, but that's the reason the
harp makers use to boost the cps (cycles per second).
Whenever I used it at rehearsals, other harp players
commented that it was "out of tune". We checked the
tuning, and my Swan was the only slide harp in the
room, with A=440 tuning. The other brands were at
442 or 443, in general.
The Swan sounded good to me, but my hearing is
suspect, especially in the upper octave range. So,
I sold it to another slider.
Best Regards, Stay Healthy
JB