The electric guitar.  Loud.  A documentary.  Yuck.  Well, no.    This must have been an immense challenge to create something worth watching about the electric guitar and rock and roll that could engage you, move you, and inspire you.  I have seen and heard this film twice now.  It moves me to tears.  Makes me chuckle.  And I take note.  Today, I recommend you get it and do the same.  Davis Guggenheim, who won an Oscar for An Inconvenient Truth with Al Gore, directs this visually beautiful film.    Here’s how they solved the problem.  They got three guitarists from three different …