The fourth Asia+ Festival will open with a cross-border celebration of contemporary music, as the “TRI-ART!ON” Concert brings together bands from Hong Kong, Mongolia, Korea and Thailand.   Led by Hong Kong music producer Carl Wong, the concert will feature a local host band alongside three Asian acts, each bringing traditional influences into modern sounds.   Mongolian heavy metal band Uuhai, making its Hong Kong debut, combines metal with instruments such as the horsehead fiddle and Khoomei throat singing. Korean rock band KARDI blends the traditional geomungo with female vocals, while Thai indie group KIKI creates a laid-back urban sound with electronic grooves and dreamy textures.   Together, the musicians will explore the meeting points between tradition and contemporary pop across different cultures and genres.   The concert will be held at 7.45pm on September 23 and 24 at the Hong Kong Cultural Centre Grand Theatre.