Episodic memory (EM) and working memory (WM) are negatively affected by healthy ageing, and additional memory impairment typically occurs in clinical ageing-related conditions such as amnestic mild cognitive impairment (aMCI). Recent studies on musical mnemonics in Alzheimer’s dementia (AD) showed promising results on EM performance. However, the effects of musical mnemonics on WM performance have not yet been studied in (a)MCI or AD. Particularly in (a)MCI the use of musical mnemonics may benefit the optimisation of (working) memory performance. Therefore, in the present study, we examined the effects of musical presentation of digits consisting of pre-recorded rhythms, sung unfamiliar pitch sequences, and their combinations, as compared to spoken presentation. Furthermore, musical expertise was assessed with two perceptual tests and the Self-Report Inventory of the Goldsmiths Musical Sophistication Index. Thirty-two persons with aMCI and 32 cognitively unimpaired older adults (OA) participated in this study. Confirming and extending previous findings in research on ageing, our results show a facilitating effect of rhythm in both cognitively unimpaired OA and persons with aMCI (p = .001, η
2 = .158). Furthermore, pitch (p = .048, η
2 = .062) and melody (p = .012, η
2 = .098) negatively affected performance in both groups. Musical expertise increased this beneficial effect of musical mnemonics (p = .021, η
2 = .090). Implications for the future design of music-based memorisation strategies in (a)MCI are discussed.