Track List 01 Hair in the Air (Sung By 예리, 런쥔, 제노, 재민) 02 Best Day Ever (Sung By 해찬, 천러, 지성) 01 Hair in the Air (Sung By 예리, 런쥔, 제노, 재민) Korean Lyrics by 이스란 / JQ Composed by Jeannie Lurie / Mia Minichiello / Matias Mora Arranged by 최진석 《Hair in the Air》是一首流行舞曲风格，保留原曲的轻快感和活泼感并加入强烈的鼓奏和说唱，使氛围更加欢乐的歌曲。歌词描述了人们被困在担忧和烦恼中，没能发现世界既美丽又愉悦，所以鼓励人们寻找真正的幸福的正面信息。 歌曲由和Trolls主角波比的形象很符合的Red Velvet YERI以及NCT DREAM的仁俊、JENO、渽民共同参与，充分展现出各成员的特色。 02 Best Day Ever (Sung By 해찬, 천러, 지성) Korean Lyrics by JQ / 현지원 Composed by Alana Da Fonseca / Jordan Yaeger Arranged by 추대관 《Best Day Ever》是一首轻快的乐队演奏和清凉的铜管音相互协调令人印象深刻的School Rock风格歌曲。歌词描述了不要犹豫，一起享受即将像梦境般展开的幸福日子的信息。就像充满活力的Trolls主角波比和布兰一样，以明快的旋律为特色，并由NCT DREAM的楷灿、辰乐、志晟参与录制让歌曲更加活泼生动。