Shinsadong Tiger, a renowned composer of hit K-pop songs such as "Up and Down" and "Roly-Poly," died at age 40 on Friday, music industry sources said. The musician, whose original Korean name is Lee Ho-yang, was found collapsed in his workroom by an acquaintance. Upon arrival at the scene, first aid workers, summoned by a call, found him already deceased. The cause of his death remains unknown. Debuting in 2001 as a music producer and songwriter, he rapidly rose to prominence, composing numerous chart-toppers throughout the 2010s, including "Roly-Poly" by T-ara, Apink's "NoNoNo," EXID's "Up and Down" and Momoland's "Bboom Bboom." Most recently, he worked as a chief producer of TR Entertainment, where he launched girl group Tri.be.