Best new songs today: Darkside, Assertion, great-grandson of Hank Williams

Coleman Williams, aka IV, the son of Hank Williams III and the fourth generation of the Hank Williams’ line, shared his hard rock country debut 'Son of Sin', singed as IV and the Strange Band; Darkside - the duo of Nicolás Jaar and Dave Harrington - shared 'The Limit', a laid-back noisey dark-club tune; Assertion share an emo/post-hardcore song 'Deeper in the Shallow'.