Tong Soon has taught in the Anthropology, Asian Studies, Medical, and Music faculties at Durham University (UK), Emory University (US), Chinese University of Hong Kong (CUHK), National Taiwan Normal University (NTNU), Lehigh University (US), and the National University of Singapore (NUS). His research focuses on East and Southeast Asian music, particularly on Singapore, and on music in cognitive health and community care with clinical practices in Singapore.

Tong Soon’s portfolio includes "Chinese Street Opera in Singapore" (University of Illinois Press 2009), 嶺南八大曲初探：歷史與文獻典藏 (A Preliminary Survey of the Cantonese Eight Song Cycles in South China: History and Sources) (co-ed. CUHK 2015), the NTNU "Echoes of Asia" workshop-concert series (artistic director and curator 2016-2017), "Routledge Handbook on Asian Music: Cultural Intersections" (ed. Routledge 2021), and "Through Other Ears: Asian Musical Encounters" (co-ed. forthcoming). His research has been supported by grants from Hong Kong, Singapore, Taiwan, UK, and the US, including the Social Science Research Council and American Council of Learned Societies (1997), The British Academy (2000), Chiang Ching-Kuo Foundation for International Scholarly Exchange (2006, 2011), and the Research Grants Council of Hong Kong (2014, 2016).

Tong Soon studied the piano with Rena Phua (Singapore) and Graeme Humphrey (London) and holds the Licentiate of the Royal Schools of Music and the Trinity College of Music, London in piano performance. As a student of Endang Sukandar in Bandung, West Java, Tong Soon also specialises in the West Javanese suling (vertical bamboo flute). He studied West Javanese gamelan degung with the late Euis Komariah (1949–2011) and Andrew Weintraub, Central Javanese gamelan with René T. A. Lysloff, and Korean drum-dance with the late Lee Yong Tae (d.2012) at the Seoul Institute of the Arts, South Korea. At Emory University, he was the founding director of the world music programme and the Asian Music Festival (2012, 2013) which comprised seven student ensembles in Chinese music, gamelan degung, Korean samul nori, Korean kayagum, Hindustani music, Carnatic music, and Tibetan folk music.

Tong Soon was appointed the Secretary General (2021-2025) of the International Council for Traditions of Music and Dance, following on from his role as the General Editor (2018–2022) of the Council’s flagship journal (since 1949) "Traditions of Music and Dance" when the journal transitioned to the Cambridge University Press. He has served as a council member of the Society for Ethnomusicology (SEM) (2000–2003), editor of the SEM Newsletter (2000–2006), Chair of the Local Arrangements Committee for the SEM 50th National Conference (2005), a member of the SEM Board of Directors (2007–2009), and of the Editorial Advisory Board of the SEM Translation Series (2008–2014). He has also served as the President of the Society for Asian Music (2007–2011), a member of the Ethnomusicology Advisory Committee of the College Music Society (2008–2010), and of the US State of Georgia's Department of Education Fine Arts Advisory Committee (2008–2010), as the Chair of the Program Committee for the International Musicological Society East Asian Regional Association Conference (2015), and on review panels at the National Endowment for the Arts (US) and the National Arts Council (Singapore).