The word 'spiroid' has been applied to generalise visual representations of musical pitch or frequency-domain data that arrange the octave intervals (a doubling of frequency Hz value) on radii of a two-dimensional circular form, thus producing a spiral line either of points (if discrete note-pitches are to be shown) or as a line representing a portion of the frequency-dominan continuum.

define spiroid:
  using a polar coordinate system to show frequency-Hz values as points on a plane, where
  → 'pitch-class' corresponds theta-angle part of the coordinate
  → and the radius-amplitude part corresponds to the 'octave-level'