The prohibited rebetika (Greek "urban blues") songs he recorded and released in his adopted country in the early 1970s became his life's work, making him popular in Greek diaspora communities around the world.
The long-play album "Otan Kapnizi O Loulas" (1973) became an artistic and commercial achievement for Nikolaidis, as well as an impetus for other artists and groups to follow with similar recordings of their own.