Ok, i came from neither high schools but i do have a lot of collegemates from these 2 schools right now (currently in ADMU which ironically is filled with LSGH guys haha don't worry i won't be biased)
The stereotype (according to my LSGH and AHS friends and they both agreed with it) is that LSGH produce more singers like oggie alcasid while AHS produce more bands like kjwan.
But honestly i dont think these stereotypes really hold up. I have a classmate from LSGH who is a total shred god that can outshred all the AHS axe-wielding men i know (then again i only know a handfull of AHS people so i wont really generalize that he can outshred AHS as a whole). Then again, i know a guy from southridge who can outshred him hehe (peace dudes) But yep. a lot of AHS guys are really in to progressive music.
Hehe but now as a whole, i can still say that it's really not in the school. I've heard really good bands from either sides eh. Some of which are tansan ni gaston from AHS and dalandan soda from LSGH
In the end, its not about the school dudes *peace!