The 25-year-old 'Talk Dirty' hitmaker was nearing the end of his set at the Jannus Live outdoor venue in St Petersburg when the sound was cut off to comply with a noise ordinance curfew.
DeRulo was not allowed to finish his concert properly and took to Instagram to apologise to his fans for the abrupt ending.
"St Pete! I'm so sorry the venue cut me short!! I didn't get 2 (to) end properly! I owe you! If it were up to me I would have continued. (I don't care) about being fined or anything like that but they cut the sound system!!!!" he wrote.