Middle C (c’ / MIDI note number 60) is called C3 in Ableton, and the piano roll ranges from C‑2 to G8.

In music theory, the same note is referred to as C4, with octaves extending from C‑1 to G9.

Many VST libraries display keyswitches according to the C4 convention. To save you some headaches when entering parameters for articulations and to avoid mistakes, you can switch the KSEM user interface to C4 here.