a hum of happiness

At times happiness comes in great, fantastic bursts.  Imitating thunderclouds or symbols crashing at the end of a song.  The great climax after the building of marvelous tension. A delectable release or realization or perhaps a thrilling lurch from deep down in the gut.

At other times it's nothing more than consistent murmur of contentment.  A hum of happiness, if you will.  Security or maybe even trust.

I don't know quite what it is.  But it's nice.