The steel sculpture whirls upward, towering more than two stories tall. Observed at the right angles in the right light, a violin and guitar reveal themselves. “Harmonic Ascension,” the new centerpiece of the Las Vegas Civic Center &Plaza, is the work of artist Cliff Garten and his Los Angeles Cliff Garten Studio. “I wanted something that was dynamic and celebratory, so the piece is comprised of two instruments, which are hidden inside of it,” he said in a phone interview. “They spiral up to create their transformation and create another form that looks like a dancing figure.” Garten and his team were in Las Vegas this week, finishing the exhibit’s installation before Las Vegas publicly celebrated a lighting and dedication Thursday night. “This sculpture is the finishing touch for the Las Vegas Civic Center,” Mayor Shelley Berkley said in a news release.…