The phrase "little guitar" refers to a smaller version of a regular guitar. It means a small musical instrument that looks and plays like a guitar but is smaller in size. Full definition
I love tattoing riding motorcycle play guitar hangin out with friends and having a good time like to party and life a little (doulike.com)
Well, it's actually four minutes, but you imagine an incessantly repeating little guitar riff over a synthesised banjo and drum machines and you can easily see how time could seem to stand still. (movie-wave.net)
And that's before you get to his slappy - scrappy hitting, the bunting and the speed, the tendency to dance in the dugout or pretend his bat was a little guitar... (sbnation.com)