On the subject of amps,  I just got my son one of those Danelectro
mini guitar amps,  which runs on a 9v battery,  and is about the size
of an old transistor radio.  It's just a bit too big for a shirt
pocket,  but not by much.  I got it for $10 at Musicians Friend. 
I tried playing my harp through it,  and once I was able to eliminate the
feedback by turning the tone and distortion all the way down,  it actually
had a killer sound.  Talk about portable.  It makes my Pignose look
like a Marshall stack (well not quite),  but it would do the job nicely for
playing on a street corner.  It's got a dirty little sound to it.  Oh
yeah,  the guitar doesn't sound to shabby through it either.  Tone
down,  distortion up,  my son's rockin'.  If he can tear it away
from me that is.

P.S.: I have no affiliation with Musician's Friend.  Just thought it
was a good deal to pass on to y'all.

 

Peace,

 

Kevin <><