Party mode — shared room with multi-device queue

[LoggeL]

Problem

Karaoke is a group activity but MelodAI is currently single-user. At a party, one person controls the laptop while others shout requests. There's no way for guests to browse songs or add to the queue from their phones.

Proposal

A party/room mode where one device is the "host" (playing audio on speakers) and other devices can join as "guests" to browse, search, and add songs to the shared queue.

Host

• Creates a room (generates a short join code, e.g. ABCD or a QR code)
• Plays audio and displays lyrics on the main screen (TV/projector)
• Has full playback control (play/pause, skip, remove)
• Sees who's in the room

Guests (phone/tablet)

• Join via code or QR scan — no account required (or optional)
• Can search songs and add to the shared queue
• Can upvote/downvote queued songs (affects order)
• See current playing song and queue, but no playback control
• Optional: "next singer" assignment per queued song

Technical Approach

• WebSocket (Socket.IO or native WS) for real-time sync
• Room state lives on the Flask backend in-memory (or Redis for persistence)
• Events: queue_add, queue_remove, queue_reorder, playback_update, room_join, room_leave
• Guest UI: lightweight mobile-optimized page at /party/{code}
• No audio streaming needed — guests only see metadata + queue

MVP Scope

1. Room creation with join code
2. Guest search + add to queue
3. Real-time queue sync
4. Host-only playback control

Future

• QR code display on host screen
• Voting/priority system
• "Up next" singer assignment
• Song request limits per guest

Complexity

High. Requires WebSocket infrastructure, room state management, and a separate guest UI. But this is the killer differentiating feature for a karaoke app.