Or, it could just mean 6 of one and half-a-dozen of the other. Maybe they were considered equivalents by the writers.

These or other similar words.

I can't find that in GIRM. In the Missal they do not occur in prayer, but only describing the exhortations to the people, e.g. before the renewal of baptismal promises.

Noel,
Hawkins is objecting to my comment, not yours. He may also be objecting to Charles' post.

In "✗ wild generalisation" I was objecting to the sentence in the title as completed by Noel, the OP.
Occasionally the observation is spot on - the first use (apart from the two quotations from the Council of Trent §11), "the Mass or the Lord's Supper" §17 would have been contentious, I suspect. Most of the time it arises naturally from describing a wide range of celebrations, rather than the OF rubrics which just address a Low Mass or a Solemn Mass (and, until 1962, had to be quietly modified for Missa cantata).
We could debate the successes and failures of the attempt to distinguish spatially between the Mass of the Catechumens and the Mass of the Faithful.

GIRM has a section on 'Particular Ministries' beginning at §98 - acolyte, lector, psalmist, schola, cantor/choir director, ... . The proper place for the psalmist is the ambo, from which they chant/read the Responsorial Psalm, and the Gospel Acclamation. the proper place for the cantor/choir director is 'another suitable place from which they can direct the congregation'.

From the ambo only the readings, the Responsorial Psalm, and the Easter Proclamation (Exsultet) are to be proclaimed; likewise it may be used for giving the Homily and for announcing the intentions of the Universal Prayer. The dignity of the ambo requires that only a minister of the word should stand at it.

That is the ideal, in addition of course to the the priest, a deacon or two, and cross bearer, candle bearers (two or four), thurifer, ... . In practice even at a Sunday celebration there is unlikely to be a psalmist distinct from the other ministers, and this role will be filled either by a lector reading from the ambo or by the cantor (or another member of the schola/choir) singing from another 'suitable place'. (Or if the arrangement of the sanctuary facilitates it, a singer may adopt the role and proceed to the ambo.)
Of course it is expected that most Masses will be on weekdays and with little or no singing. Westminster Catheral has 29 read Masses and 10 sung Masses a week, our remote country town has 6 or 7 read and two or one sung. GIRM has to address the full range of possibilities and resources.

Surely the Missal has never "addressed the full range of posibilities and resources", or there would have been no need for Fortescue and his predecessors. The first paragraph of Fortescue on Missa Cantata without Deacon or Subdeacon: The More Solemn Form, shows that it is not in conformity with the published rubrics, though it does not say that in as many words but talks of custom sanctioned by the bishops. But in the UK and the USA in most parishes that was what happened at the principal Sunday Mass - p.137 in the 1918 edition.

Touché!

I understood it to be that the options are permitted, but not necessarily preferred.

It is no secret that the ideal Mass is fully sung and celebrated by the bishop, with inter alia a singer functioning (at least at this point of the liturgy) as a dedicated psalmist. And that this psalmist should discharge their function at the ambo. And it is obvious that GIRM covers everything from that situation to a weekday Mass without musicians (which should not mean without music). The "ambo or another suitable place" is a simple, and clear, recognition that the ambo is liturgcally preferable, but there may be good reasons to use another place for singing, as Earl_Grey says.

...and even less employed