Chicago rapper Calboy came up with other artists from his city who adopted part-sung, part-rapped flows and moody beats for a more melodic approach to typical trap production.

His early mixtapes were a less-refined version of this style, but around the time of 2018's "Envy Me," he perfected his sound.

The song's raw narrative about gang violence and the heartlessness required for street life met with Calboy's hooky melodic vocals and resulted in a viral hit.

Mixtape Wildboy is the rapper's first effort for major-label RCA.

It begins with "Envy Me" and the project's other nine songs largely follow the formula of the tested hit, with eerie trap beats made up of floating synth pads and booming 808 thumps creeping along at mostly the same bpm while ghostly vocal samples drift through the background.

Calboy's tales of young strugglers made up much of his early work and he revisits his leaner times on tracks like "Ghetto America," while relationship issues are the main theme on songs like "Love Me." Other Chicago rappers from Calboy's camp show up on the brief collection as well.

Lil Durk appears on multiple tracks and Polo G contributes to album standout "Caroline." Seasoned players Young Thug, Meek Mill, and Yo Gotti also offer verses on several tracks.

"Envy Me" is the star of the show on Wildboy, and while most of the songs stay in a similar lane, the last few tracks get into more adventurous production and point toward even further creative evolution on work yet to come.