In the 70s he released two albums under the name Oasis (!!) in the euro-disco style, singing in English.
He has also numerous releases as Vagelis Pitsiladis (singing in Greek or English) and some very nice scores for films and TV series.
Below 3 different samples.
First coming from Oasis Lp Yes I Do (1978). It's a euro-disco instrumental.
Oasis - Tycoon (1978)
Second sample is from Oasis 1979 Lp Call Me Now. A more soulful track.
Oasis - Conquistador (1979)
Last one is from 1979 LP Vagelis Pitsiladis - Agapi Mou (My Love). It's a cinematic instrumental track which starts easy to become a nice psych groove.
Vagelis Pitsiladis - Fthinoporo (Autumn) (1979)