This article reports a study on a musical idiot savant (NP) who is capable of memorizing large-scale pieces of piano music in three or four hearings. Attempts to memorize two contrasting pieces are documented, one a tonal composition by Grieg, the other an atonal piece by Bartok. The results are compared with those provided by a professional pianist. Transcription of the reproductions shows that NP's ability is confined to tonal music and is structurally based. In this respect, it resembles the performance of high IQ memorizers and supports the view that general intelligence is not a prerequisite for structure-based skill.