Piano Man
... that boy band member Gongchan plays the pianist in the music video for Mamamoo's "Piano Man"?
... that boy band member <a href="./Gongchan" id="mwBRY" rel="mw:WikiLink" title="Gongchan">Gongchan</a> plays the pianist in the music video for <a href="./Mamamoo" id="mwBRc" rel="mw:WikiLink" title="Mamamoo">Mamamoo</a>'s "<b id="mwBRg"><a href="./Piano_Man_(EP)" id="mwBRk" rel="mw:WikiLink" title="Piano Man (EP)">Piano Man</a></b>"?