MANSFIELD, Mass. — It ain’t easy being Kanye West. Just ask him.

One of the most dynamic performers in the hip-hop game, West has in the past shared the stage, and his irrepressible energy, with a string section and with pianist-singer John Legend. Last night’s show at the Tweeter Center, however, set him alone on a moonscape after crashing his spaceship during the final leg of his journey “to find some new inspiration.” This led him to spend a lot of the show on a raked platform with his band hidden and nothing but chilly synths and computerized voices to keep him company. It wasn’t just Kanye against this world but a couple of others, and his attempts to get home were the driving force of a rather forced narrative overlay to the show.

There were some impressively angst-ridden moments, particularly on the opening song, “Good Morning,” and some of the songs on last year’s Graduation album that were already covered in chilly synths, particularly “Good Life” (though in many places the band drowned West out). And there were some humorously over-the-top moments, such as the visit from a space-alien chick to sing Journey’s “Don’t Stop Believin’” and tell him “the world needs you.”

But it left him at a curious remove from the audience, and songs such as the slyly funny “Gold Digger” lost something in the attempt to switch to an earthbound method of transmission; his shout-outs to the ladies during “I Wonder” also felt academic. Visually, he was banking on his silhouetted figure to deliver an iconic punch, and while it is distinctive, it’s not exactly Jordanesque, at this point anyway.

West’s lyrical ambiguity and his sometimes-clumsy delivery is occasionally frustrating and usually compelling; “Cant Tell Me Nothing,” alternately angry “I ain’t one of the Cosbys/ I ain’t go to Hill, man”) and hopeful (“And you can live through anything if Magic made it”), was a good example. Still, West’s emotional appeal and high-strung persona came through on the earnest, direct sequence of “Jesus Walks” and “Hey Mama.” The latter was particularly affecting for its laid-back musical setting (and, of course, the added context of West’s mother’s death last year), even though West’s vocals in the singing choruses were weak.

West tried to make up for lost time during the coda of “Touch the Sky,” where he proclaimed his devotion to “the future leaders” in the audience and promised that “the real is what I’m gonna give them.” That’s been true in the past, but last night his speech was a jarring contrast to the mostly chilly, self-involved show that preceded it.

Rihanna preceded West singing (and doing some lip-synching) with a live band, which had its strengths and weaknesses. The extra volume of the setting worked well with the Euro-disco pounding of “Don’t Stop the Music” and gave muscle to the monster hit “Umbrella,” but the band over-muscled her early, immaculately produced hits “Pon De Replay” and particularly the bouncy “S.O.S.,” whose “Tainted Love” sample template would have been nearly undetectable to anyone who didn’t know it was there. While she makes a decent 21st-century dance diva, her attempts at the classic diva thing during ballads such as the acoustic guitar-driven “Hate That I Love You” or the piano ballad “Unfaithful” fell flat on her nasal voice.

“You ADHD?” Pharrell Williams asked over and over during N.E.R.D.’s first song, “Anti-Matter.” Well, I know you are, but what am I?

Utilizing distorted synthesizers, two drum sets, bass, guitar and the frontman trio of Williams, Shay and Chad Hugo, N.E.R.D. tore through a set of mostly new songs from its upcoming album Seeing Sounds, which combined the aesthetics of hip-hop, heavy metal and, I don’t know, the Transformers theme? It was compelling, energetic, messy and sprawling in all the best ways. The highlights included an extended romp through their latest single, “Everyone Nose,” mixing electronic dance-floor banging with ominous minor-key synth muscle and a chaotic workout on the aptly-named “Spaz.” The breakout hit “She Wants to Move,” from 2004’s Fly or Die, was tame by comparison.

Chicago-based Lupe Fiasco opened the show with the rapid-fire flow set off by the gentle ’70s-soul inspired beats. He had only a DJ for musical backing, but plenty of company on stage from singers Nikki Jean and Matthew Santos, who handled the introductory hooks on such songs as the road-inspired “Paris, Tokyo” and the dramatic “Streets of Fire,” from this year’s pseudo-concept album The Cool, respectively. Fiasco made a quick nod to his first hit, “Kick, Push,” and ended with the psychodramatic “Day Dreamin’,” off his first album, Food and Liquor.

rmassimo@projo.com