I am looking for a specific, distinct name for the first beat in the first bar. The anacrusis or pickup measure should not be considered.
This is for a label in a software for playback-based performances. I want to annotate the time position of the "first beat of the piece" for synchronisation with a click track.
Note: The clicks do not require to start exactly at the mentioned point in time, it's just the reference point for synchronisation. There could well be a count-in like "1,2,3,4", then the next "1" is actually the beat I am referring to.
Note2: Assume, for this question, that the BPM and time signature remain the same for the whole piece.