MIDI note and controller numbers are off by 1. Sigh.

Please pardon this totally noob question.

I’ve checked out various MIDI controllers and software,
then compared them with TD’s MIDI Device Mapper dialog.

When I play a middle C (MIDI = 60), the console displays a MIDI message of 80 3c XX.
Since 3C is hex for 60, the message is arriving correctly, the same way it works for all other software.

Touch Designer, however, gives the note an index of 61.
This odd behavior happens with controller messages, too. Controller 1 appears as index 2.

I can go into my MIDI In CHOP and turn off 1-based indexing for that CHOP, but why? Why should that be necessary at all? Why is TD trying to make me sad?

Les

Mac OS 10.11.6
TD 2017.10940