The English Gradual has Gregorian chant tones for the propers from the Anglican Missal. It can be imposing for clergy (and choirs) who do not know how to read music, but would still like to chant the propers from the missal for high mass. But fear not! It is not as hard as it may appear. Here's the trick:
The English Gradual, in just about every case, uses the same tones for the various parts of the mass. Tone VII is used for the introit; Tone V for the Gradual; Tone VIII for the Tract (if there is one); Tone VI for the Alleluia; Tone II for the Offertory; and Tone I for the Communion. So, the priest or cantor simply has to memorize the tune (get someone to pluck it out on the piano for him), and then make various adjustments for the words and phrasing for each liturgy. Albeit, the constant use of the same tones would get old, but at least it is a start.
Many continuing parishes cannot afford nice organs or full time, skilled organists. But it is still possible to have nice, sung liturgies under those circumstances. Chant can be used instead. And if the priest and a few other members of a parish get together and practice chanting (form a "gregorian schola"), some real aesthetic beauty and mystery in worship can occur.
A lot of priests can't chant well because it is not taught in seminaries much anymore. What they need to do if they want to learn is go buy chant cds (by groups like Chanticleer, or the Tallis Scholars) and carefully listen to way trained singers chant and try to imitate them. The key is: knowing the tune; proper pronunciation; proper phrasing (chanting is NOT like regular singing).
