Euphony means harmony in sound. In other words, the total opposite of cacophony. Think harps and babbling brooks, not pots, pans, and muffler-less Harleys.
Apparently Edgar Allan Poe was a fan of euphony. Or at the very least, he seemed downright thrilled with it in his poem "The Bells". Wallace Stevens, too, was no stranger to euphony in his poem "Thirteen Ways of Looking at a Blackbird", although those blackbirds probably aren't helping the harmony much.