For each psalm there is at least one version in metre, with a tune in that metre. Almost all of the tunes are of the type of traditional hymn tunes. They do not, though, have to be sung that way.
We are all familiar now with the Common Metre hymn, Amazing Grace. Most people may be surprised to be told that until the Royal Scots Dragoon Guards produced their pipe version of it in the 1970s, this tune, New Britain, was almost unknown in the UK. If known at all, it would have been sung in a regular four part harmony version to organ or piano, with no gracing and no rhythmical fluidity. As such, that makes a depressingly dull tune. If one listens to the typical British congregation singing what is now a well known hymn, they instinctively and unwittingly still add grace notes where a piper puts them.
There is every good reason to do similar things with any tune. No arrangement that is out of copyright is sacrosanct. Any tune that dates from before about 1850 will originally neither to have been sung nor played in the style of a typical robed choir accompanied by the organ.
Most people will be aware that the original English Hymnal introduced a number of tunes that were arrangements in hymn style of traditional folk melodies that had been collected by folkloric enthusiasts of the time. There is no reason why one should not reverse engineer them.
There are few examples in this collection of tunes presented in ‘folk’ style rather than conventional hymn style, with a melodic line with suggested guitar chords.