Parque Hidalgo, the small square immediately north of the Cathedral, fills with chairs from the surrounding restaurants every evening, and from about 8pm the marimba bands start. Marimba — the large wooden xylophone instrument that is central to Yucatecan and southern Mexican music — is performed here nightly, free and in the open air, as it has been for generations. The surrounding restaurants serve food and drinks at tables arranged around the park; you do not need to buy anything to listen, but the atmosphere is better if you do.
This is one of the easiest and cheapest ways to experience Mérida as a musical city. The marimba repertoire covers traditional Yucatecan pieces, Mexican popular standards, and sometimes requests from the audience. The quality of the bands varies but is consistently good. The restaurant tables fill up early on weekends; arrive by 7:30pm if you want a seat with a good view of the musicians. The park and the evening concerts are used entirely by locals and visitors in roughly equal measure — it is not a performance staged for tourists but a genuine municipal tradition.