In a thick British accent, a charming and spirited Alexander Prior, guest conductor for the Las Vegas Philharmonic, discussed love, his own musical interpretation of Tchaikovsky’s “Romeo and Juliet,” and the broad spectrum of the human spirit last Saturday at Ham Hall.

A hint of nervousness might have been expected from Prior, who is barely 18 and already a prolific composer. But maybe conducting a professional orchestra is old hat when you’ve been doing it since age 11, were commissioned for work by the Moscow State Ballet at 12, studied at St. Petersburg Conservatory and have conducted at gigs internationally.

Brought in as the first guest conductor for the Philharmonic’s Rising Star Series, Prior had spent the previous week working with the orchestra on the collaboratively selected Valentine’s-themed program: Nielsen’s “Helios Overture, op. 17,” Vaughan Williams’ “Norfolk Rhapsody No. 1 in E minor,” Tchaikovsky’s “Romeo and Juliet Overture” and Beethoven’s “Symphony No. 4.”

“Helios Overture,” set in Greece, and referred to as “One of the greatest and fun horn tunes to play” by Prior, began soft and delicate, then grew deliriously joyous, before returning to its quiet state. The Tchaikovsky piece was clearly made Prior’s and garnered a standing ovation. Beethoven’s Fourth was whistle clean. Returning to stage for his third bow, Prior darted from the wings, through the string section, arms in the air.