Hitting the Right Note: How to Play Custom Songs in Project SEKAI

If you’ve spent any time tapping away at Project SEKAI: Colorful Stage!, you’ve probably hit a point where you thought, “Man, I wish I could play my absolute favorite Vocaloid track here, even if it’s not officially in the game.”

Because Project SEKAI has a closed, official song rotation managed by SEGA and Colorful Palette, you can’t simply upload an MP3 straight into the main mobile app. However, the rhythm game community is fiercely creative. If you are looking to groove to custom charts, fan-made covers, or tracks that haven’t made it to global or Japanese servers yet, you have options.

The Reality Check: Can You Mod the Official App?

Directly injecting custom songs into the official, downloaded-from-the-App-Store/Google-Play version of Project SEKAI is heavily restricted. Doing so usually triggers anti-cheat protocols or risks getting your account banned.

Instead, the rhythm gaming community achieves the ultimate “Project SEKAI custom song experience” using a specialized companion platform designed specifically for fan-made content: Sonolus.

The Ultimate Solution: Using Sonolus for Custom PJSK Content

Sonolus is a free-to-play, open-source audio-visualizer and rhythm game engine. Think of it as a sandbox framework where players can replicate the exact UI, note skins, and gameplay physics of games like Project SEKAI, while loading community-made custom charts and audio tracks.