“The world’s on the brink,” Sean Lennon warns in a twinkling waltz cadence, backed by Les Claypool’s slap-bass convulsions. “But that’s just what the devil wants you to think/ Never stop shopping, don’t ever give in/ Cause if we stop shopping, the terrorists win.” It would be the funniest rock lyric of the year, if it were the funniest lyric in the song. “Ohmerica,” a side-splitting, psychedelic condemnation of Bible-thumping, drone-friendly America, is the centerpiece of the duo’s collaborative debut LP. (That funniest lyric? “You think George Washington evolved from an ape?/ You should be locked up in the 51st state.”) Throughout 51 batshit goofy minutes, Lennon and Claypool trade hooks, riffs and jokes with an offhand charm that would border on spontaneous were it not for the intricate musicianship on display: Claypool’s funk-finger bass work remains a band unto itself, propelling the demented peeping tom tale “Mr. Wright” and creepy-crawly “Breath of a Salesman.” Lennon’s plodding, primal drumming adds menace to the title-track’s proto-Floyd buzz and the ragged psych lurch of “Boomerang Baby.” The true surprise is his versatile guitar work, a bevy of wah-wah pedal fireworks and guttural fuzz. Monkeys, OxyContin junkies, insects and astronauts: Claypool and Lennon run the gamut of subject matter on Phobos. And they make it all sound heady and hilarious.