Kid Cudi is a rapper but Man On the Moon can’t be classified as a rap album. His full-length debut is a vast, ambitious concept album divided into five acts, each exploring a different aspect of Cudi’s psyche. Sonically, the album takes its cues from new wave and New Romantic bands, techno, and ambient music. The contributions of Ratatat and MGMT further dissolve the boundaries between electronica, modern rock and hip-hop. Despite its astrological grandeur, the album adopts a somber tone throughout. Restlessness and desolation are the subject of “Solo Dolo,” “My World” and “Sky Might Fall,” but it's the brooding, minor-key chants of “Soundtrack 2 My Life,” “Day ‘n’ Nite,” and “Pursuit of Happiness” that really set the tone for the album. Cudi repeatedly expresses his yearning to escape to outer space, and despite its upbeat finale (“Up Up & Away”), Man On the Moon ends up feeling like a hip-hop rejoinder to the astral laments and slow-motion theatrics of Pink Floyd’s Dark Side of the Moon.