I was listening to 曾经的那个人 by 梦然. You can check out the song here.
https://baike.baidu.com/item/%E6%9B%BE%E7%BB%8F%E7%9A%84%E9%82%A3%E4%B8%AA%E4%BA%BA/21270421
Or here:
https://drive.google.com/file/d/1Y7H8vfxEUA4fg0udSmUXZJzryXM_l5s-/view?usp=sharing https://www.kugeci.com/song/6i1jMQWM
In the lyrics, you can find the line that goes: 脑海中一直有一张笑脸
Edit: Please skip to 00:00:58 for this exact line.
Although the lyrics says 一张笑脸, the singer says 一道笑脸.
Did I spot it correctly or is it some sort of contextual sound change cause I never heard 道 could be used as a measure word for things like 笑脸 (smiling face).
Edit: I found a ton of Chinese novels where 一道笑脸 is actually used: Are all of these just mistakes?
https://www.dizishu.com/b/2682/7975833.html
这是一张怎样的笑脸,几乎就是带着冰冷死亡还有恐惧···这一道笑脸几乎是可以令所有的人,感觉到死亡的窒息!即便是中年的面色,也都刷的一下剧烈变化!
https://www.biquyue.com/book_38294/26564.html
方莫吞了口唾沫下去,望着面前这些人,脸上尴尬而又得体地露出了一道笑脸:“各位好啊?”
http://www.biquge5200.net/47_47238/18117207.html
伊莉雅勉强露出了一道笑脸:“谢谢你,对了,我还不知道你的名字。”
https://m.sz-tman.com/du/84219/19855417.html
下一刻眼前就已经是出现了一道冷冷的笑脸,随着这一道笑脸刚刚出现的同时,就令他心中一沉!
https://www.booktxt.net/7_7451/49436751.html
顾景迁还企图隐瞒,努力扬起一道笑脸,解释道:“没事,我只是有些累了,沐恩,现在还没有辰修的消息,一有消息我一定会……”
http://m.xiaoshuopu.com/xiaoshuo/62/62534/28885872.html
当莫天能主动放过一些生灵的时候,其嘴角终于是露出一道笑脸。
For more examples, you can check this link: https://www.google.com/search?q=%22%E4%B8%80%E9%81%93%E7%AC%91%E8%84%B8%22&newwindow=1&client=firefox-b-d&ei=vLc3YZ-0C-ug5NoPrOeHkAE&start=20&sa=N&ved=2ahUKEwifgs36xu3yAhVrEFkFHazzARI4ChDy0wN6BAgBEDU&biw=1440&bih=830