# Theory of Happiness — FTISLAND

<https://hit-masters.com/en/tracks/ftisland-theory-of-happiness-ivtsWSkxkgo>

[Home](https://hit-masters.com/en) › [FTISLAND](https://hit-masters.com/en/artists/ftisland-UCeYes53L01fdS4SiNv-ldxw) › [Theory of Happiness](https://hit-masters.com/en/albums/ftisland-theory-of-happiness-MPREb_ILpqYdWpxWX) › [Theory of Happiness](https://hit-masters.com/en/tracks/ftisland-theory-of-happiness-ivtsWSkxkgo)

“Theory of Happiness” by FTISLAND. From the album Theory of Happiness (2025). Certified Demo (Common) in HitMasters, the music trading card game.

| Field | Value |
| --- | --- |
| Artist | [FTISLAND](https://hit-masters.com/en/artists/ftisland-UCeYes53L01fdS4SiNv-ldxw) |
| Album | [Theory of Happiness](https://hit-masters.com/en/albums/ftisland-theory-of-happiness-MPREb_ILpqYdWpxWX) |
| Year | 2025 |
| Length | 4:07 |
| Certification | [Demo (Common)](https://hit-masters.com/en/ranks/demo) |
| YouTube Music plays | 1,000,000 |
| YouTube Music | [https://music.youtube.com/watch?v=ivtsWSkxkgo](https://music.youtube.com/watch?v=ivtsWSkxkgo) |

## The certification

Certification for songs whose popularity index ranges from 0 to 640,000. Published odds per record pulled: 70%. Rarity: Common.

## More by FTISLAND

- [Because I Don't Know How to Love (2023) (사랑하는 법을 몰라서 (2023)) – FTISLAND (Gold Record)](https://hit-masters.com/en/tracks/ftisland-because-i-dont-know-how-to-love-2023-2023-CYrgl6Yo5xQ)
- [Unthinkable – FTISLAND (B-Side)](https://hit-masters.com/en/tracks/ftisland-unthinkable-gsDWu5pyaWQ)
- [BURN IT – FTISLAND (B-Side)](https://hit-masters.com/en/tracks/ftisland-burn-it-UgBfFHvXNnY)
- [Sage – FTISLAND (B-Side)](https://hit-masters.com/en/tracks/ftisland-sage-BMGX9lLdPk0)
- [Serious – FTISLAND (B-Side)](https://hit-masters.com/en/tracks/ftisland-serious-pnrmW_Man7I)
- [Like The First Day – FTISLAND (Demo)](https://hit-masters.com/en/tracks/ftisland-like-the-first-day-apZeMNBM5Gw)
- [Lemonade – FTISLAND (Demo)](https://hit-masters.com/en/tracks/ftisland-lemonade-rsmaqPWGBzE)
- [The rose of Versailles (Original Soundtrack from the Webtoon The Siren : Becoming the Villain′s Family) – FTISLAND (Demo)](https://hit-masters.com/en/tracks/ftisland-the-rose-of-versailles-original-soundtrack-from-the-0rrHGzrs0Z8)

## Other songs certified Demo

- [Que Mala Vida – Camilo Sesto (Demo)](https://hit-masters.com/en/tracks/camilo-sesto-que-mala-vida-P1m7AGAXT-k)
- [Que Mala Vida – Camilo Sesto (Demo)](https://hit-masters.com/en/tracks/camilo-sesto-que-mala-vida-IY74PuKkZvk)
- [Mineirinha – Gusttavo Lima (Demo)](https://hit-masters.com/en/tracks/gusttavo-lima-mineirinha-H_zJRNmmP-s)
- [Men Awal Afrah – Abdul Majeed Abdullah (Demo)](https://hit-masters.com/en/tracks/abdul-majeed-abdullah-men-awal-afrah-q6-1o6C7KXg)
- [Lilly (Live) – Antonello Venditti (Demo)](https://hit-masters.com/en/tracks/antonello-venditti-lilly-live-gqF7ClHkZI0)
- [Nice Thing – Biga\*Ranx (Demo)](https://hit-masters.com/en/tracks/biga-ranx-nice-thing-c4lDhnbwBiw)

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Songs, cover art and plays: YouTube Music. HitMasters, the music trading card game.