Eleven Psalms mention ‘the Korahites’ in their titles, and 1 Chronicles 9:19 refers to Korahites ‘in charge of the work of the service’ of the Temple, specifically ‘guardians of the thresholds of the tent.’
Korah occurs ten times in genealogies (Genesis 35; Exodus 6; 1 Chronicles 1:35; 2:43; 6:22 and 37). In both Numbers 16 and 1 Chronicles 6 he is a descendent of Levi; however, in Genesis he descends from Esau, seemingly a different family altogether.
Numbers 16 names Korah as one of the leaders of a rebellion against Moses which concludes with him and all those associated with him being engulfed in something like a massive earthquake (‘The earth opened its mouth and swallowed … up … everyone who belonged to Korah … . So they with all that belonged to them went down alive into Sheol … ,’ Numbers 16:31-32). This leaves the problem of a rebel family wiped out in the wilderness returning later as Temple officials. It may be that the Numbers tradition preserves an attempt by a group inimical to the Korahites to discredit them. The Rabbinic explanation is that Korah’s sons survived and repented.
The Hebrew root qrḥ means ‘to be bald.’ There is speculation that the Korahites might have shaved their heads. On a more light-hearted note, it is ironic that one group of descendants of Esau (famously ‘a hairy man’) could be described as ‘bald.’
Firth, D. G. “Asaph and Sons of Korah.” Pages 24-27 in Dictionary of the Old Testament: Wisdom, Poetry & Writings. Edited by Tremper Longman III & Peter Enns. A Compendium of Contemporary Biblical Scholarship. Downers Grove, IL: InterVarsity Press; Nottingham, England: InterVarsity Press, 2008.