Will a PS2-to-GameCube Adapter Work for Guitar Hero III on Wii?

No. A PS2-to-GameCube controller adapter cannot work with Guitar Hero III on Wii.

Why It Fails

• Different Protocols: PS2 controllers use proprietary wired protocol. GameCube ports expect GameCube protocol. Adapters translate between these two wired standards.
• Wii Guitar Controllers Are Wireless: Wii guitars connect via Bluetooth to the Wii Remote (which plugs into guitar) or directly via Wii's Bluetooth. They don't use GameCube ports.
• No Signal Translation Path: PS2 → Adapter → GameCube Port → ??? → Wii Bluetooth. No device bridges this gap.

What You Actually Need

• Wii Guitar Hero Guitar: Wireless guitar designed for Wii (works with all Wii/GH games).
• Wii Remote + Guitar Grip: Some guitars use Wii Remote as transmitter.
• Compatible Third-Party Wii Guitars: Look for "Wii compatible" labeling.

Backward Compatibility Note

Wii can use GameCube controllers (via top ports) for GameCube games only (e.g., Super Smash Bros. Melee). Wii games require Wii Remotes.

Buy a proper Wii guitar—adapters won't bridge this technology gap.