This weekend on The iHeartRadio Countdown with Mario Lopez actor Skylar Astin will be checking in! The season finale of his hit show 'Zoey's Extraordinary Playlist' is airing Sunday night so he's dropping a little preview on us. Plus he's got a bunch of other projects in the works and has a ton of music knowledge. So we'll catch up with him, countdown the top 20 songs in the country and more! Tune in!