"sing your heart out" in Chinese (Simplified)
全情投入地唱尽情歌唱
Definition
用很多情感、精力和热情地唱歌，通常很大声或很投入。
Usage Notes (Chinese (Simplified))
这是一个非正式且积极的表达，表示鼓励某人尽情唱歌，常用于卡拉OK或演唱会。不是字面意思唱关于心脏，而是表达情感。
Examples
At the concert, everyone began to sing their heart out during the chorus.
音乐会上，大家在副歌部分开始**全情投入地唱**。
Don’t be shy—just sing your heart out!
别害羞——大胆**全情投入地唱吧**！
She loves karaoke and always sings her heart out.
她喜欢卡拉OK，总是**尽情歌唱**。
When he gets on stage, he really sings his heart out every time.
他每次上台都**全情投入地唱**。
Nothing feels better than getting together with friends and singing your heart out to old songs.
没有什么比和朋友们聚在一起**全情投入地唱**老歌更开心的了。
He may not have the best voice, but he sure knows how to sing his heart out.
也许他嗓音不最好，但他真的懂得**尽情歌唱**。