Following the success of last year's SMKA Productions The 808 Experiment mixtape, which included the various underground sounds that give flair to Atlanta's hip-hop scene, producers Blake "808 Blake" German and producer/engineer Kyle "7King" King are at it again. Another gathering of beatmakers, MCs and personalities convene to celebrate the release of THE 808 EXPERIMENT, VOL. 2. The CD mashes up a wide array of street-hardened grit, smooth R&B and a deluge of lyrical prowess that paints a picture of the state of the ATL in 2010. Nappy Roots, Hollyweerd, A.leon Craft, Niko Villamor, Rahbi, Slimm Duddy, Stanza, Grip Plyaz and more are lined up to throw down. Listening session: Free. 6 p.m. Wish, 447 Moreland Ave. 404-880-0402. wishatl.com. Release party: $8. 9 p.m. Star Bar, 437 Moreland Ave. 404-681-9018. www.starbar.net.