OFFBEAT — Rhythm Trainer

Drill the genre-specific "gap" — offbeats, swing triplets, backbeats — with millisecond feedback. Auto Bluetooth latency calibration. 30-day courses keep you on track.

OFFBEAT is a rhythm training app built for ska punk and jazz musicians.

■ Train the "gap" a metronome can't teach you Just tapping along with a metronome doesn't build the feel you need on stage. OFFBEAT focuses on the genre-specific placement of rhythm — offbeats only, the third note of the swing triplet, the 2 & 4 backbeat — and visualizes your timing error in milliseconds.

■ 6 specialized training modes

• Offbeat Master — the 8th-note offbeat that underpins ska cutting
• Swing Pocket — the "third triplet" feel of jazz time
• 2 & 4 Backbeat — the shared backbone of jazz and ska
• Silent Keep — hold your internal groove through bars of silence
• Tempo Sprint — survive accelerating tempos without rushing
• Call & Response — hear a phrase, play it back

■ Automatic latency calibration Measures the output delay of your earphones/speaker and folds it into the judgment, so latency doesn't make you look "off" when you're not. That said, we recommend wired earphones or a speaker for serious timing practice, since Bluetooth latency itself fluctuates.

■ Built to keep you coming back

• Three 30-day lesson courses (All-round / Ska focus / Jazz focus)
• Day-streak tracking with a weekly one-day protection freeze
• Timing diagnosis after every session: are you rushing or dragging?
• Score, accuracy and average offset recorded every run

■ Privacy All play data stays on your device. Nothing is transmitted (see the privacy policy for details).

For you if:

• You play in (or want to join) a ska punk or jazz band
• You can follow a metronome but can't sit in the groove
• You've ever been told you rush on the offbeats

— From the developer I've played in a ska punk band and spent years touring the jazz cafés of Japan, yet I never trusted my own sense of rhythm. Metronomes and method books didn't fix it. "It isn't talent — there has to be a way to train this." So I built it with the one skill I did have: programming. That's how OFFBEAT began. Not for people who already have rhythm, but for those who struggle, like I did. Starting with ska and jazz — and someday, for every player, in every genre.