Garibaldi is a place in Mexico City where musical groups and party planners go to meet up and make deals. The musicians also play for tourists, each tune for a price.
I went in the afternoon looking for harpists, and found Alfonso Garcia, harpist with a conjunto jarocho group called Los Cocuyos. Here's his picture:
I got his contact info and we tentatively planned that I would visit him at his shop tomorrow (his card says "construction and repair of harps"). However, as he explained, this is tentative because the top priority will be to land a gig for this important holiday weekend (Dia de los Muertos, "Day of the Dead"). If the meeting comes of I'll write more, otherwise this is it.