Complex sentence: In February 2016, Taeyeon released the single Rain "as the opening single for S.M. Entertainment's digital music project SM Station, which also peaked atop the Gaon Digital Chart and additionally charted at number three on" Billboards World Digital Songs.
Split into simpler sentences: In February 2016, Taeyeon released "Rain" as the opening single for S.M. Entertainment's digital music project SM Station. The single peaked atop the Gaon Digital Chart and charted at number three on the "Billboard" World Digital Songs.