Banyak kenangan masa lalu yang tidak pernah dulu lagi. Mereka seperti domino, jatuh dan pecah menjadi potongan-potongan kecil. Itu terlambat untuk mengumpulkan kembali.

Domino adalah single digital pertama dari grup idola Korea 1THE9. Rilis pada tanggal 7 April 2019 sebagai track pre-release untuk album mini debut mereka XIX.

Single ini memiliki dua versi, yaitu versi Korean dan English. Lagu ini menampilkan vokal Crush, yang juga menjadi bagian dari duo duo musik Korea Crush & Lil Nas X.

Lirik lagu "Domino" seperti berikut:

[Verse 1: Jung Jin-sung, Sin Ye-chan, Yu Yong-ha, Lee Seung-hwan]
Oh, don't you know
I'm just pretending to be okay
I was drunk yesterday and didn't want to sleep alone

Don't you know
I've never been like that before

[Refrain: Jeong Tae-hyun, Jun Do-yul]
You're the only one I think of, and I don't even notice other girls' eyes
Why is it like this? No way

[Pre-Chorus: Sin Ye-chan, Jung Jin-sung, Kim Tae-woo]
Every time, every night
I'm trapped in your fence, just wanting to be alone

Chorus:
We're like Dominoes falling down
Falling down, falling down, falling down
Dominoes falling down
Falling down, falling down, falling down

[Verse 2: Park Sung-won, Yu Yong-ha, Sin Ye-chan, Lee Seung-hwan]
Honestly, our trust is already broken
Like a shattered window, it's impossible to put back together again

The dust in our relationship has become thick
And the more we try to hide it, the harder it gets

[Refrain: Jeong Tae-hyun, Jun Do-yul]
You're the only one I think of, and I don't even notice other girls' eyes
Why is it like this? No way

[Pre-Chorus: Sin Ye-chan, Jung Jin-sung, Kim Tae-woo]
Every time, every night
I'm trapped in your fence, just wanting to be alone

Chorus:
We're like Dominoes falling down
Falling down, falling down, falling down
Dominoes falling down
Falling down, falling down, falling down

[Hook: Kim Jun-seo]
You're like a domino, my trust is crumbling
I'm like a domino, your love is breaking
You're like a domino, my truth is hurting

[Bridge: Lee Seung-hwan, Sin Ye-chan, Kim Jun-seo, Jeong Tae-hyun]
All the broken pieces are shattered beyond repair
It's too late to put them back together again

I'll just leave it all behind and move on