I don't know what a "surprisingly high" number is - but the mission is about 1/3 Spanish speaking as far as I can tell[1].
[1] It's hard actually, but this language diversity data(https://www.sf.gov/data/san-francisco-language-diversity-dat...) says there are ~20k speakers and this district population breakdown (https://www.sfgov.org/ccsfgsa/current-san-francisco-supervis...) says there are ~67k residents
Spanish language pop music is also just extremely mainstream and popular in the United States, and has been for decades.
This is looking about 90% Spanish songs and 10% reggae-fusion.