Combine Hollywood's hottest host with America's longest running weekend countdown and you've got American Top 40 with Ryan Seacrest.Every week, from the heart of Hollywood, Ryan counts down from number 40 to the hottest hit in America. AT40 brings you the best of music and entertainment, with news and gossip you'll hear nowhere else.The American Top 40 app provides these great features:. Get the AT40 weekend chart in the palm of your hand. Send a song request or email the show. Listen to the AT40 stream 24/7 from iHeartRadio. Read music and entertainment news articlesNote: Usage of the live stream on the EDGE, 3G, 4G or LTE networks may result in additional data charges. Please check with your provider for more details.