During the late 1960s, he met poet and lyricist Nikos Gatsos and fellow composer Manos Hatzidakis at a cafeteria which was a well-known haunt for musicians and artists (Flokas).
The first song Moutsis wrote was 'Βρέχει ο Θεός' ('God is raining'), a piece he had already composed the music for and for which Gatsos provided lyrics.
Over the next few years, he continued to write songs with Gatsos which were recorded by well-known artists of the time such as Vicky Moscholiou and Grigoris Bithikotsis, as well as with newcomers such as Manolis Mitsias and Dimitra Galani.
In 1970, Moutsis orchestrated and produced the music for album 'Επιστροφή', with songs by Hatzidakis and Gatsos.
During the same period, Moutsis worked with other lyricists such as Lefteris Papadopoulos.