A summer evening in Stoneham has a sound all its own — mowers winding down, kids out on the common, Route 28 easing off toward dusk. YARD MUSIC INC works inside that sound, cutting lawns on a steady weekly beat, trimming the corners a mower can't reach, and running a clean edge along walks and driveways. Spring opens with a cleanup that clears the winter's litter out of the beds; autumn closes with leaves off the grass before the first hard frost pins them there. Yards in this town are close together, so a tidy one carries down the block and makes the whole street feel looked after. Straight lines, sharp edges, everything blown clear — that's the note to end on.