Literature Reference: 击节独长謌，其声清且悲。—— 《续古诗十首 三》 白居易 Beating time, I sing a long song alone, its tone both clear and sorrowful. Source from 'Xu Gushi Shi Shou 3' by Bai Juyi.
长: Strengths, merits.
謌: The same as "clamor" or "uproar."
Meaning: The long song signifies profound emotions and steadfastness in heart.