At my church this past Friday, I attended an evening Mass that commemorated the Feast of Our Lady of Guadalupe. Unfortunately that's not all that was celebrated. The Mass seemed to be about being Mexican as much as anything else. Celebrations of ethnic heritages might be good in and of themselves, but not during Mass. The main harm in this case is that the message of Our Lady of Guadalupe was diluted by considerations that were, at best, ancillary. Somehow I cannot think of Saint Juan Diego attending anything with mariachi music; in fact that genre of music was not contrived at the time.
Far better for these sorts of Masses to simply focus on the saint or event at hand rather than introduce ethnic celebrations within it. Else the real spiritual meaning is lost in all the extraneous clutter. Another feast day that suffers similar abuse is St. Patrick's Day. How the feast day of the apostle to Ireland get sidelined by people dressing as leprechauns, dying food and hair green and even drunken carousing is beyond me - and I'm of Irish descent.
At the Mass this past Friday, the congregation was devout. Whether or not the mariachi lyrics were helpful I could not tell as I don't speak Spanish (it was overly loud, though). What I hope we never see again is the de facto night-club performance that disgraced St. Peter's Basilica, with Pope Francis as the main celebrant. Catholic Family News has a full analysis on that and I'd suggest you read it. I've no doubt that St. Juan Diego spun in his grave as this performance unfolded.