Reintroduce Sung Liturgy of the Hours on Sundays and Holy Days.

Interesting suggestions so far.

Presuming this is a Catholic cathedral you've taken on, my first suggestion is to join CRCCM and engage with their membership—we have a strong email list for this sort of discussion, and of course our annual gatherings are invaluable. Your cathedral might already be current on their membership (it's the middle of renewal season), so membership might be as easy as emailing updated info to the treasurer (me). If it's not, it's only $65/year, so there's no reason not to be.

On my general philosophy towards change in leadership—don't be in a hurry to change things, and make sure your pastor is 100% behind you if you're going to implement a seismic shift. I've seen so many fail because of these things. Take time to understand where the parish is before you craft a plan to bring them where they need to be. There's no rush.

Also, since you have Spanish masses also, I'll just bring your attention to the fact that there's a new set of Spanish responsorial psalms that have been written for the Houston co-cathedral available on the CRCCM Repertoire Project. (https://repertoire.crccm.org)

All the best,
Marc

I couldn't agree with Trenton more.

Once the priests start singing [well] much else will follow. This has the added benefit that the priest can condition the people to sing the responses, even when a choir is not present, and the congregation just gets used to singing many more parts of the mass by osmosis. This is an area where my pastor (who is musically trained) has put in a lot of effort, and five years later, I can tell you it has made a huuuuuge difference. People know all the responses very well, and consequently, will even sing them at daily mass when prompted to do so. All unaccompanied, all very strongly. The other reason to do this is that it raises the "baseline solemnity" of the parish. So even your simpler masses still contain many a cappella sung parts, rather than being completely silent. People learn that when they come to mass, they sing.

Bombarde made an interesting comment about treating all the masses the same. I can tell you that this is what we do at our parish, to varying degrees of success. (That is to say: the elderly saturday mass participates very little, the 7:30am mass participates with medium vigor, and the 11am sings full-throated with total buy-in.) I've been rather contented with this arrangement, because then the experience of mass is reasonably "the same" regardless of which mass you attend (with the usual caveat that there is extra stuff at the choir mass for obvious reasons). It also lays the baseline expectation that at least xx amount of music will be sung at every mass regardless. This also makes it easier for people to transition between mass times whenever necessary. Few things are as disappointing as being a family that likes all the smells and bells, and for some odd reason, one week you have to attend the "folk mass" which barely resembles the mass you ordinarily attend. This way, if you attend xx parish, you know what you are going to get, plain and simple.

The obvious caveat to that is that some people who like the '[insert any troped genre here] mass' may chose to move to a different parish if that style of worship is not offered to them. That said, I find myself utterly unconvinced that it is in any way beneficial to have a folk, "normal" and "high" mass all at the same parish every weekend. For starters, at least one of those genres is really not supported by any of the documents like the GIRM or TLS, so why take pains to either introduce one, or keep one on life support? Considering the fact that cathedral parishes should be setting the tone for the whole diocese (as was recently reiterated by Bp. Klemm in his wonderful letter) it seems prudent to establish a beautiful, traditional baseline that is present at all cathedral masses.

Also, please, PLEASE introduce propers. Even if they are only in the vernacular and "in addition to". But PLEASE sing them. Other DoM's and PRIESTS will be looking to you whenever they come to a diocesan liturgy. If you do it, it will arm people in parishes where this may be a, ahem, less-welcome development to have the courage to say, "we are simply doing what they do for the bishop at his own church. We are bringing our mass into closer alignment with our high priest."

Here is a non-musical thought. You appear to have a very bilingual parish. Sometimes, the effect of a bilingual parish is actually to have two parishes who share one physical church. I would suggest that you follow the lead of the Second Vatican Council and take steps so that all parishioners can say, in Latin, those parts of the mass which pertain to them. Have all the ordinaries and all of the dialogues be in Latin at every mass, no matter which language the rest of it is in. That way, a Spanish speaker attending an English mass could participate in those parts of the mass which pertain to him or her. The same would be true for and English speaker who attends and otherwise Spanish mass. It would also allow celebrations, especially at the Triduum, where there to be only a single liturgy to have some commonality.

You could also then use the Gregorian mass settings as part of the project.

I am convinced that bilingual liturgies, of the Spanish and English flavors, do not work well in practice. There are two different sets of musical and cultural expectations working at cross purposes. In 25 years of liturgical music work, I can say that some of the most awkward liturgies have been when Spanish and English speakers are responding to prayers in their own languages and not bothering to do the same in the other’s. Ditto for hymns and Mass parts. If nothing else, it emphasized the cultural division in the room and it happened during Holy Week.

As banal as it sounds:
1. Stabilise the repertoire, including genres at each point in the liturgy,
2. Stabilise the manner of accompaniment and leadership, and
3. Ensure that a consistent set of liturgical customs prevails, through close consultation with the MCs and servers.

If these things are in place, the rest can be put into place. Without these, you're in a perpetual state of revolution.

At the risk of stating the obvious: bathe the whole process in prayer. At its best, music direction requires pastoral skills. Volunteer musicians can tell the difference.