Can You Play Original Xbox Games in an Xbox Live Party (Voice Chat)? No.

No. On Xbox One / Series X|S, original Xbox backward compatible titles do not support Xbox Live Party voice chat while playing.

Why

• Architecture: Original Xbox games run in a virtual machine (VM) that emulates the original hardware/OS. The Xbox 360/One/Series OS-level party system (Xbox Voice) cannot inject into the VM's audio pipeline.
• No Title Update: Microsoft never added the necessary hooks to the emulator to route game audio + party chat together.
• Xbox 360 Back Compat Games: Do support party chat (most of them) because the 360 emulator integrates with the One/Series OS audio stack.

Workarounds

• Discord / Mobile Call: Use a phone/tablet/PC alongside the console for voice chat.
• In-Game Voice (Rare): A few original Xbox games had their own voice chat (e.g., Halo 2, Rainbow Six 3), but the original Xbox Live service is dead. XLink Kai or Insignia (fan servers) restore in-game voice for some titles — but not Xbox Party chat.
• Local Multiplayer: Original Xbox games support 2–4 controllers on one console — no party needed.

List of Original Xbox Back Compat Games (40 titles)

Includes: Halo: CE, Halo 2, Fable, Ninja Gaiden Black, Star Wars: Battlefront II, KOTOR I/II, Jade Empire, Psychonauts, Panzer Dragoon Orta, Crimson Skies, Max Payne 1/2, Doom 3, Half-Life 2, The Warriors, etc.

None support Xbox Party Chat. Use Discord.