This mural depicting what appears to be the likeness of Union leader and labor organizer Caesar Chavez can be found on a building located on Layette Street between Canal and Howard.
However, despite the close resemblance to Chavez, the group of musicians clearly visible above his head makes me think that this man might actually be a famous musician. Sadly, I could find nothing about this mural on the Google, believe it or not.
The man depicted is playwright and poet Garcia Lorca (as it says in the writing next to him). http://c250.columbia.edu/c250_celebrates/remarkable_columbians/federico_lorca.html
Thanks, Terese! I totally see his name written on the building now that you point it out! — G