Previous research suggests that individuals with a vocal pitch imitation deficit (VPID, a.k.a. "poor-pitch singers") experience less vivid auditory images than accurate imitators (pfordresher & halpern, 2013), based on self-report. in the present research we sought to test this proposal directly by having accurate and VPID imitators produce or recognize short melodies based on their original form (untransformed), or after mentally transforming the auditory image of the melody. For the production task, group differences were largest during the untransformed imitation task. importantly, producing mental transformations of the auditory image degraded performance for all participants, but were relatively more disruptive to accurate than to VPID imitators. These findings suggest that VPID is due partly to poor initial imagery formation, as manifested by production of untransformed melodies. By contrast, producing a transformed mental image may rely on working memory ability, which is more equally matched across participants. This interpretation was further supported by correlations with self-reports of auditory imagery and measures of working memory.
Greenspon, Emma B.; Pfordresher, Peter Q.; and Halpern, Andrea R.. "Pitch Imitation Ability in Mental Transformations of Melodies." Music Perception (2017) : 585-604.