Social timing plays a concurrent and long-term role in social interactions. Cyclicity (a person's coordination of speech, body movements etc.) and synchrony (the coordination between individuals) are especially important. Synchronous interactions in childhood affect later developments, such as language development and emotion regulation. In ASD, timing and social timing are abnormal, which may adversely affect or even cause impairments. Evidence of interactional synchrony skills in ASD is sparse, therefore I sought to investigate cyclicity and synchrony skills in ASD. Video-recordings of interaction with and without music between children with ASD and a caregiver (N = 14; 2 to 8 years) were analysed using an adaptation of the well-established Monadic Phase coding scheme. Time-series analysis enabled quantification of cyclicity, level of synchrony (coherence) and significant synchrony. Cyclicity was present in most interactions (76-90%). Coherence scores ranged from .08-.39. Synchrony was present in 19% of time-series without and 60% of time-series with music. Music significantly enhanced presence of synchrony (p < .000) and indicated a trend for enhanced cyclicity (p = .058) and coherence (p = .063). No change over time was observed. Therefore, preschoolers with ASD engaged in rhythmic social timing but consistency was low and diminished compared to neurotypical infants. Music enhanced social timing considerably. No change over time was likely due to fluctuations in children's willingness to engage. Findings are limited by the lack of interrater reliability and control group. The aim of the thesis, to contribute to social timing evidence in ASD was achieved. The method successfully quantified social timing parameters, compared data to previous studies and showed that music enhanced social timing performance. Recommendations for further study include replication with a larger group, more time points, and control groups. This method could be applied to other settings to investigate the concurrent effect of music on social timing.