two songs that I can think of with maidin in the first line are Sean Ó Duibhir an Ghleanna (Ar m'eirí dhom ar mhaidin) and Siobhán Ní Dhuibhir (the Duibhir is pure coincidence). The latter was an Clannad's first album, fairly upbeat and some harmonies. But Maidin probably comes into hundreds (at least) of other songs.

I'm off to bed also. Hope you find the one you want.