It still played in rock style. Singing is little different then your aveage rock band, but it defitnley rock sounds!
The guitarist for RHCP is amazlingly good.
Yah sure some of their songs sounds like funk, but they are everything execpt pop and mainstream. Actually stadium arcadium might sound a little like pop, but majority of it actually more of funk and 90s alternative rock. The CD i have in my truck right now is from 1991 and it all rock! If they played it like the old time rock n roll then it' would sound the same IMO, so this is new ages of rock. But again I am slightly hearing impair so it hard for me notice different between all different type of genres in rock, but red hot chili pepper is still ROCK n ROLL!
Also, I do listen to guns n roses, dr. hook, ac/dc, smashing pumpkin, i do have some jimi hendrix and led zepplin, errr few others I cant think of, but I got crap load of red hot chili pepper on my ipod.