When drill erupted out of Chicago three years ago behind the rise of Chief Keef, the infamous MC brought his close circle of friends with him into the limelight. Many inked deals with major labels, though Sadiki Thirston, aka SD, went indie—he’s released a string of Life of a Savage mixtapes and a studio album, November’s Truly Blessed, which he put out through LA’s IHipHop Distribution. SD’s name is less recognizable than, say, fellow drill rappers Lil Durk or Lil Reese, but SD is exalted among hip-hop heads who follow this scene closely. SD is a known entity, but some people talk about him like he’s this city’s best-kept rap secret.

On the new Life of a Savage 4 SD explores a depth of emotions within the confines of his vocal range. On “I Wonder,” produced by shit-hot Atlanta beat maker Metro Boomin, the 20-year-old MC mulls over the endless—and potentially grim—possibilities of his life in the complicated manner of someone going through a midlife crisis. His future could be stellar, but SD sees potential pitfalls all around him. Yet if he keeps making tracks like “I Wonder” then I bet SD’s future will remain bright.