I've heard good things about the Fender Blues Junior? Is this amp only good for blues? I play hard / classic rock

Also, what about distortion / effects pedals? Are they good for this guy?
for classic rock the fender blues will be fine, probably get an OK AC/DC sound, to play hard rock get a heavy distortion pedal and play it with the amp on clean.
Get and OD like a Boss SD-1 or Tube screamer. You could get some classic rock out of it. If you got high output pickups and 2 od's maybe close to metal but I don't know. I haven't used a blues junior like that.
I have a HRD which is very similar. If I were you I would get it and through a DS-1 infront of it.
I'm probobly going to get mocked or flamed for this, but I have a Fender Blues Jr and the Boss overdrive pedals (I have an OD-3) sound much better through it than a TS9. Just my opinion for if you get one, make sure you try all different overdrive pedals - don't just believe the majority of people and assume that they have the same taste in tone as you.
what is the music theory and what does it teach you, like scales, solos, and to build speed???

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