Guitar Hero: On Tour (DS) Compatibility with Original DS

No. Guitar Hero: On Tour (2008) requires the Guitar Grip accessory, which plugs into the Game Boy Advance (GBA) slot (Slot-2).

• Original DS ("Phat"): Has Slot-2 → Compatible with Guitar Grip.
• DS Lite: Has Slot-2 → Compatible (Grip fits flush).
• DSi / DSi XL / 3DS / 2DS: No Slot-2 → Incompatible. Cannot play On Tour, Decades, Modern Hits.

Series on DS

• Guitar Hero: On Tour (2008)
• Guitar Hero On Tour: Decades (2009)
• Guitar Hero On Tour: Modern Hits (2009)

All require Guitar Grip + Slot-2. No DSi/3DS support.

Alternatives on DSi/3DS

• Rhythm Heaven / Paradise (Touch/Tap).
• Elite Beat Agents / Ouendan.
• Theatrhythm Final Fantasy (3DS).
• Taiko no Tatsujin (Touch/Drum).

If you have an original DS or DS Lite + Guitar Grip, the trilogy works well. Otherwise, play Guitar Hero Live (mobile/console) or Clone Hero (PC – free, custom songs, any controller).