In addition to my above post, which showed that the ability to detect fine-grained pitch changes is superior in individuals with High Functioning Autism, there are many other studies which have similar findings (I have included some below for reference purposes). So there is definitely relatively intact or enhanced musical pitch processing in Autism Spectrum Disorders…
What is the relationship then between this strength in ‘featural processing’ and the potential development of savant musical abilities in some people with Autism Spectrum Disorders? Savant Syndrome is where people with ‘developmental delays’ of the brain, demonstrate profound and prodigious capacities and/or abilities far in excess of those considered normal.
Heaton, P., Hermelin, B., & Pring, L. (1998).
Autism and pitch processing: a precursor for savant musical ability?
Music Perception, 15, 291-305.
Heaton, P., Pring, L., & Hermelin, B. (1999).
A pseudo-savant: a case of exceptional musical splinter skills.
Neurocase, 5, 503-509.
Heaton, P. (2003).
Pitch memory, labelling and disembedding in autism.
Journal of Child Psychology and Psychiatry, 44, 1-9.
Heaton, P. (2005).
Interval and contour processing in autism.
Journal of Autism and Developmental Disorders, 8, 1-7.
Mottron, L., Peretz, I., & Menard, E. (2000).
Local and global processing of music in high-functioning persons with autism: beyond central coherence?
Journal of Child Psychology and Psychiatry, 41, 1057-1065.
(source: http://www.sedsu.org/Pdf/Heaton_04.pdf)