Σάμερον άδιον άσω is correct.
Σάμερον is Doric for Σήμερον (=Today)
άδιον is Doric for ήδιον, the comparative form of the neuter "ηδύ" (=sweeter).
άσω is a future form of άδω, αείδω (=sing)
It translates as "Today I shall sing more sweetly / I shall sing a sweeter song".
Another line with "άδιον" is "Άδιον ουδέν έρωτος", Nothing is sweeter than love.