This paper presented at the Neo-Babylonian Network Meeting in Amsterdam on 29 May 2017 discusses the absence in first-millennium sources of the aspects that in third- and second-millennium sources could be connected to what we may call the third-gender characteristics of the kalû. I argue that the kalû probably did not loose this feature but that the first-millennium sources simply do not reflect on them anymore: first of all, there are no indications that the tasks and nature of the kalû as the performer of (emesal) cult songs changed fundamentally from the second to the first millennium. Second, it may be due to the different nature of the source material that the third-gender aspects of the kalû are not reflected upon anymore: the first-millennium ritual texts dryly list the offerings and prayers of the kalû, contrary to the earlier literary (mythological) texts which portrayed the kalû as the devotee of Ishtar and crosser of boundaries (such as Inanna's Descent to the Netherworld).