Beltr

Beltr is a desktop karaoke system for Mac, Windows, and Linux that turns your existing music into karaoke tracks. It scans your music folder or Apple Music library without copying or converting anything. It uses a neural network to remove vocals, syncs lyrics, maps pitch, and identifies the key. The song is ready to play as soon as it's singable.

The system transforms your TV into a stage with word-synced lyrics, a pitch bar, live scoring, and a leaderboard. A room code and QR appear on the screen for guests to join via their phones without needing to install an app or create an account. Guests can queue songs, adjust vocals, send reactions, and track their scores. Free apps for iPhone and Android allow phone-as-microphone functionality, and TV apps put Beltr on the television.

Beltr can also read existing karaoke files such as CDG, MP3+G, .kar, .mid, and Thai NCN. Lyrics and timing are taken directly from the file. Songs can be exported as .kar or burned as MP3+G and CDG for use with a hardware karaoke machine.

There's a practice room feature that can slow songs to 50% speed without changing the pitch, loop difficult sections, and track weak lines. Users can record performances as shareable vertical videos.

The system operates locally, without the need for cloud processing, accounts, telemetry, or an internet connection once a song is ready. Beltr costs $19.99 with lifetime updates and covers two devices. Five songs are free without requiring a card or signup, and there's a 14-day refund policy. The interface is only available in English.Built by a solo developer (CasaVargas LLC).