keystring VERY interesting! I'm glad that worked out for you. I was taking the macrobeat to be the same as the "main pulse" -- that is the "ONE" of each measure. It definitely is the focus of rhythmic alterations such as ritardando -- which you accurately describe as a lengthening of the distance from the first "One" to the next "One' -- essentially a reduction in tempo.
From a pragmatic viewpoint -- i.e. getting students (and myself) to connect their intellectual understanding of rhythm with their kinesthetic experience of rhythm -- walking -- but transforming it from "automatic" -- almost sub-consciously -- to consciously. I've found the activities I described helpful -- eventually connecting whole-body movements to the metronome. Once the connection is beginning to come together, then obviously the metronome comes into play. From my own experience I find the metronome necessary to "re-calibrate" my brain -- to re-program the sense of the exact distances of the macro and micro beats. I'm not sure if it works the same for everyone, but for me, repeated exposure to the calibrated distances, and constantly re-synching the auditory with the kinetic somehow "sticks" in the brain -- i.e. trains the brain to thereby replicate those distances when the metronome is absent. At times I've taken the metronome down to the eighth note or even sixteenth note level to precisely program the distances, then backed out to larger levels, To smooth out pieces I have set the metronome to the "One" level which seems to encourage a more musical flow and smooth out the granularity of individual notes.
Here's what Google's AI had to offer:
A macrobeat is the "big beat" or main pulse in music, providing the longest and most heavily weighted beat that organizes the rhythm. It serves as the framework for smaller, faster pulses called microbeats, which divide the macrobeat and help define the meter (duple or triple).
The "big beat": The macrobeat is the pulse you feel when you naturally sway or step to the music, such as the downbeat in a waltz or a march.
Divides into microbeats: The macrobeat is divided into smaller, equal parts called microbeats. For example, in duple meter, each macrobeat is divided into two microbeats; in triple meter, it's divided into three.
Drives the tempo: Macrobeats are primarily responsible for our perception of the music's speed or tempo.
Defines the meter: When combined with microbeats, macrobeats establish the musical meter, or the pattern of strong and weak beats.
Audiation vs. notation: The concept of macrobeat and microbeat is based on how music is heard (audiated) rather than just its written notation, which can sometimes be misleading
I also found this interesting:
https://theimprovingmusician.com/course/course-introduction-2/
