Getting your Trinity Audio player ready... Happy to announce that “The Sound of Music,” at Segerstrom Center for the next 10 days, remains a satisfyingly spry 66 years old, its enduring, endearing appeal largely in place in this touring production. Through astonishingly engaging earworm melodies, smart, sincere and heartfelt lyrics and a universal theme of a damaged family made whole by a naive outsider helping them persevere, Rodgers & Hammerstein’s final musical fails to age or fade.