Photo by John Nova LomaxMilton Martin downtown on the corner of Main and McKinneyMilton Martin spends his days blowing his soprano sax from his wheelchair in the bright sun at the corner of Main and McKinney, hard by the assemblage of broken dreams and frustrated town planning that is Main Street Square. Over an everyday assemblage of abject, bullyragging winos, hard-looking dudes with neck tats, and occasional cubicle slaves, Martin's sweet-toned soprano sax can be heard rising with its mocking