After sharing a fruitful musical partnership that yielded electronic music with a sci-fi twist for nearly fifteen years, brothers Phil and Paul Hartnoll conclude their Orbital project with Blue Album, their best album to date. We're not talking Jay-Z pseudoretirement here, either -- they're probably done. "Transient" starts off with an ambient and almost Unplugged feel, but two songs later the duo ramps it up with "Tunnel Vision," and the tempos subsequently fluctuate like the wind. Meanwhile, the hurly-burly, rave-reminiscing song "Acid Pants" confirms that their tongue-in-cheekiness is still intact. Orbital sounds freer on Blue Album than ever before, which makes this disc bittersweet for its fans.