Okay kids:

Whole bands do not stick to just one scale "mostly". Whole songs don't usually do that.

So I'd advise that you give an example of a few tunes you mean, and then we can give you somewhat of an idea of what Fruciante is using for those songs.


fake edit: Sorry if I'm being harsh, it's just that this question gets asked every second day, and it's so ambiguous that it bugs me.
Am - Gmaj - Dm - Am

F5 - C5 - D5 - G5

The solo looks to mostly be in A minor pentatonic/A natural minor. Makes sense, especially considering the i-bVII-v-i progression in Am in the verse.

Wow theory is scary it makes me feel insecure
Looking to buy a Fender Jagstang, u sellin?