are you referring to music such as perotin or gesualdo (a
bit later)? in those instances, the composer may have focused less on
the outcome but wouldn't the "lines/counterpoint" still be a function of the
harmony, although it may be incidental.
i have a hard time believing that the end result (i.e. the
harmony) was happen-stance, not that i disagree with anything that's been
said; rather, personally i have a difficult time understanding writing a
"line" that doesn't take into consideration the "chord" it forms with other
instruments playing different "lines".
i may be going nowhere with this. if so, please
forgive.
-jim