Hello and Welcome. I note that you are a new member. This link will provide you with a guide to concerts (including free concerts) in Buenos Aires:
https://www.labolsa.com.ar/agenda/coro-nacional-de-ninos-y-ninos-cantores-de-basilea/ https://www.bn.gov.ar/agenda-cultural/concierto-de-piano-lidia-ksiazkiewicz https://buenosaires.gob.ar/noticias/continua-el-ciclo-vientos-de-otono-en-el-centro-cultural-san-martin...
baexpats.org
It is posted by the member Jatango (I hope I have spelled that correctly). If you do a quick search of threads with some key words (like dancing, tango, etc.), you may find more suggestions and resources. I would encourage you to look beyond Recoleta (which is a lovely area) unless you have reason for staying near to that area for practical reasons this weekend. Thanks and welcome to a beautiful city. Jay