While today the membership of Belsize Square Synagogue comprises people who have joined from other strands of Judaism alongside the families of its founders, this history is reflected especially in the dignity of its religious services, mainly conducted in Hebrew, and its music.

This was mainly composed by Louis Lewandowski (b.1821), who was based in Berlin and influenced by Felix Mendelssohn, and by Salomon Sulzer (b.1804), a Viennese cantor and contemporary and friend of Franz Schubert.

Religious services are held every Friday evening and Saturday morning and on Jewish festivals and Belsize Square Synagogue is known by its music led by Cantor, Choir and organ following the German Liberale tradition and composers Louis Lewandowski (Berlin) and Salomon Sulzer (Vienna) between others.

Belsize Square Synagogue services are live-streamed via its website, with the support of grant funding from the Six Point Foundation, and by a donation from the Ann Hirschfield Trust.

In conjunction with volunteers, the synagogue's community care co-ordinator provides support and assistance to older members of the congregation and others in need including those experiencing bereavement or ill-health.