PentaMonochord vs ZZZ Polyrhythm

The Pythagoreans’ foremost innovation was to correlate pitch relationships to calibrated speaking lengths of a string on a monochord. Now, for the first time, there’s an app for that! Use IntervalBlocks to build a two-octave G pentatonic scale on the PentaMonochord using only octaves and fifths. Touch any block to see and hear its interval again, and watch the Hertz box to see how the frequencies of the two notes relate inversely to the string lengths represented by the IntervalBlock. Touch the note labels any time to play a pentatonic tune. Press “Switch to Game” to join the Pythagorean pantheon by building the whole scale with the minimum number of steps. The Intro and the Background Information explain the monochord system in detail, and the Timeline puts it all in perspective.

Zzz Polyrhythm is a polyrhythm-focused metronome that lets you layer multiple rhythms simultaneously for advanced rhythmic practice. From classical 2-against-3 to jazz shuffle to contemporary 7-against-11 — instantly build any rhythm pattern you can imagine and play it back with professional-quality voices. Key Features [Base Beat — the time-keeper] - Time signature: any numerator (1-16) and denominator (2 / 4 / 8 / 16) - BPM: precise control from 30 to 240 - Tap Tempo: detect any tempo in real time - 8 voices: Wood Block / Click / Cowbell / Sine / Square / Tick / Hi Click / Low Thud [Layered Rhythms — Overlay] Layer additional rhythms on top of the base beat to construct complex polyrhythms. - Starting beat: not only "beat 1, beat 2" but also fractional positions like "beat 1.5" - Length: whole / half / quarter / eighth / sixteenth / thirty-second note × none / dotted / double-dotted - Subdivisions: any tuplet from 2 to 11 - Shuffle mode: play only the first and last clicks for a jazz swing feel - Timing offset: slide the start/end positions back and forth to fine-tune swing - Voice: choose an independent voice for each overlay from 8 sound presets [Visualizer] Concentric ring display lets you see rhythm timing at a glance. A dot lights up the moment each click fires, helping you grasp polyrhythm structure visually. [Presets] (Premium) Save your favorite rhythm configurations with custom names. Recall with one tap. Browse multiple presets and switch any time. [Phase-preserving BPM changes] Change BPM in the middle of a beat — the rhythm doesn't reset, it smoothly accelerates or decelerates, just like a professional studio metronome. Who it's for - Drummers / percussionists training complex rhythmic sense - Jazz / fusion players developing swing feel - Instrumentalists practicing 3-, 5-, 7-tuplet figures - Composers / arrangers analyzing multi-voice rhythm relationships - Performers studying traditional cross-rhythms and contemporary music Languages 日本語 / English / 中文 / 한국어 / Español / Português Switch languages manually from the hamburger menu, or have the app follow your device's system language. Free vs Premium [Free] - Base beat + up to 2 overlay layers - All 8 voices / any time signature / BPM 30-240 - Tap Tempo / Shuffle / full feature access - Discreet banner ad + occasional interstitial [Premium (Ad-free)] - All ads removed - Add 3 or more overlay layers (unlimited) - Save / load / delete rhythm presets Subscription Details - Title: Premium (Ad-free) - Length: 1 month, auto-renewable - Price: 180 JPY / month Payment will be charged to your Apple ID account at confirmation of purchase. The subscription renews automatically unless it is canceled at least 24 hours before the end of the current period. Your account will be charged for renewal within 24 hours prior to the end of the current period. You can manage or cancel your subscription anytime in your App Store account settings after purchase. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://smolt-stage.com/home/privacy/zzz-polyrhythm-privacy-policy-ios-en.html Developer SMOLT STAGE, K.K. © 2026 SMOLT STAGE, K.K. For questions and feature requests, please use the in-app feedback form. We hope this contributes to your musical practice.