Answer:
All described below.
Step-by-step explanation:
I) Lined hymns are also called "precenting the line" in Scotland or lining out. It is a form of call and response hymn singing in acapella or the singing or composition of hymns whereby a religious leader mostly referred to as "precentor", gives a different tune to each line of a hymn the way he wants the congregation to sing it after which the congregation Now sing in a chanted form after the precentor has given the tune.
Meanwhile Shape note singing is a traditional form of social singing from music books which are usually printed in shape notes. These shape notes are a variant of the Western musical notation system in which the note heads are printed in clearly different shapes in order to indicate their scale degree and solemnization syllable of which the most common syllable is "fa, sol, la".
II) The contrast between the two types of music is that Shape note singing is Polyphonic which means that it involves producing or involving many sounds or voices whereas lined hymn singing is hetrophonic which means it is one that is done with simultaneous variation of a single melodic line.
III) They are considered archaic because they were popular in the centuries back when people didn't have couldn't read and didn't also have good means of effectively learning hymns with their tunes compared to today where many people are now educated and there are a lot of resources available to us to aid our singing even for those who are deficient in reading and learning fast.