+ (null? (cdr simple-elements))
+ ;; special case: if this simple_element has a HarmonicEvent in its
+ ;; 'articulations list, it should be interpreted instead as a
+ ;; note_chord_element, since \harmonic only works inside chords,
+ ;; even for single notes, e.g., < c\harmonic >
+ (null? (filter (make-music-type-predicate 'HarmonicEvent)
+ (ly:music-property (car simple-elements) 'articulations))))