The Mix 99.1 21st Century Summer Celebration Mix 99.1 and McGowan Water present a 21st Century Summer Celebration! Join us this Independence Day for the hottest summer songs of the century. All-day Sunday, July 4th Mix 99.1 is highlighting songs that have been the soundtrack to your summer celebrations. When you think water, think McGowan. When you think Today’s Best Music, think Mix 99.1.