Chad Gilbert, the founding guitarist and backing vocalist of the punk rock band New Found Glory, died on Sunday. He was 45. The band and Gilbert’s wife, Lisa Cimorelli, confirmed his death on Instagram, writing in a joint statement that he “passed away peacefully in his sleep” with “his wife and mother by his side, just as he wished.” “We are devastated and shocked by how quickly he left us, yet so grateful for how peacefully and smoothly he went,” the statement read. “The amount of visitors that crowded the hospital lobby at a moment’s notice is a testament to how beloved and cherished Chad was, and always will be. He was a legendary…