Northwest Harmony Chorus, a local Sweet Adelines group, will celebrate World Singing Day with a free Barbershop Extravanganza concert featuring several local outstanding vocal groups from 2 to 5 p.m. Oct. 15 in the Royal Durst Theatre at Vancouver School of Arts and Academics, 3101 Main St., Vancouver. Vocal groups will include Northwest Harmony Chorus, Columbia River Chorus, Pride of Portland Chorus, Bridge Town Sound and the Vancouver School of Arts and Academics chorus, as well as several quartets. Masks are required for the audience. The family-friendly event is free, although donations are gratefully accepted. Raffles and door prize drawings will be offered.