If they have to travel to week evening rehearsals, could you try offering alternate weekday and Sunday-after-Mass rehearsals if there is at least an hour's gap between Masses
If a significant number are working, they will only be available on Sundays, so not for example the Triduum.
If I joined a parish choir I would expect to sing every Sunday, solemnity, Ash Wednesday, the Triduum, and anything else that comes up. I would also expect weekly rehearsals at the minimum as well as extra longer rehearsals during Lent and Advent. Furthermore, I would expect to be expected to practice at home and be prepared to rehearse at rehearsal.
(leaving aside my objections to the term "perform" in a liturgical context)People's lives are very busy. I encourage you to be thankful for their dedication and enjoy when are able to perform. I have been in parishes where this would have been like manna from heaven. It may change over time. You never know.
Do they have rehearsal aids to practice at home? Is there a core of interested singers who want to sing any chance they get?
If I joined a parish choir I would expect to sing every Sunday, solemnity, Ash Wednesday, the Triduum, and anything else that comes up. I would also expect weekly rehearsals at the minimum as well as extra longer rehearsals during Lent and Advent.
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