Somascape : MIDI Ways — MIDI note number mapping:
The MIDI note numbers 0 to 127 map to musical notes as shown in the following tables. Note that although most manufacturers label this range as C-2 to G8, with middle C being C3 (as I have here), you may come across some manuals that describe this range as C-1 to G9 (with middle C being C4).
Handy chart I found to get my numbers straight.
Of course this chart is Yamaha-centric. I have Logic Pro X set to use C3 as middle C.
from the internet — “According to Roland it is C4, according to Yamaha it is C3, according to International Scientific Pitch it is C4.”