[7] Lemmer studied at the Belzer Cheder in Borough Park, and attended the Mir Yeshiva in Jerusalem, living in Israel for six and a half years.
Before becoming a full-time singer, Lemmer was the director of marketing at a technology firm start-up based in Williamsburg, Brooklyn.
[14][7][6] He also still works as a cantor during the High Holidays at Congregation Ahavath Torah, a Modern Orthodox synagogue in Englewood, New Jersey.
[12] The music on his November 2019 major label debut album, The Perfect Dream,[1] is produced by Jon Cohen and accompanied by London's Royal Philharmonic Orchestra.
[6] During the coronavirus pandemic, Lemmer was recruited by the Department of Health and Human Services to raise awareness about the virus to Orthodox Jewish communities.
[20] In March 2023 Lemmer released his third studio album, Kiddush Hashem, which he produced himself, as well as serving as the co-composer for some of the songs.