note transformer:
global = import ly | scale=twelve-r | key=b-min | trem-speed=12
    | grace-place=0 | grace-dyn=1
>zh = standard-strings | import china.zheng | bent-string | trem-speed = 10
y = ly-track
ly-gliss = ly-post glissando

-> = +accent

note generator:
e->q = tempo '\markup { \concat {
    ( \smaller \general-align #Y #DOWN \note #"8" #1
      " = "
      \smaller \general-align #Y #DOWN \note #"4" #1
    )
} }'

q->e = tempo '\markup {
    \concat {
        ( \smaller \general-align #Y #DOWN \note #"4" #1
        " = " \smaller \general-align #Y #DOWN \note #"8" #1
        )
    } }'