Terms of Use for Partwise

Partwise: Music Theory Published by OFO Labs

Last Updated: September 2026

Please read these Terms of Use carefully before using Partwise. By downloading or using the app, you agree to these terms.

Acceptance of Terms

By accessing or using Partwise, developed and published by OFO Labs, you agree to be bound by these Terms of Use. If you do not agree, do not use the app.

The App

Partwise marks four part harmony. You are given a bass line and its figures, you place the upper three voices by dragging noteheads on a staff, and the app checks the result against the rules of common practice part writing and draws every fault where it happens. It runs entirely on your device.

What We Promise About the Marking, and What We Do Not

We think this belongs in the terms rather than only in the marketing.

Partwise checks a real rule set. Parallel fifths and octaves, direct fifths and octaves between the outer voices, voice crossing, overlap and spacing, voice ranges, chord tones, doubled and unresolved leading tones, unresolved sevenths, incomplete chords, augmented leaps, and bass notes that disagree with the figures. It contains a solver that realizes every exercise itself under the same rules, which is why it never sets an exercise it cannot complete and never shows an answer it would mark wrong.

What it is not is your teacher. Part writing has a settled core and a wide margin, and reasonable teachers differ at the edges: on when a direct fifth is acceptable, on doubling in inversions, on how strictly to treat an unequal fifth. Partwise marks one defensible convention, the one taught in most harmony courses, and it names the rule it applied so that you can disagree with it knowingly.

Read Partwise for whether your voice leading holds together, and read the explanation under each mark for why. Do not read a clean page as a promise of a grade. Nothing in the app is advice about an examination, and we are not responsible for a mark you receive after using it.

Not Affiliated With Any Examination Board

Partwise ships no examination questions, no syllabus text and no material from any publisher. The exercises are figured bass progressions written for this app and expressed as Roman numerals, and everything else is computed from them on the device. We are not affiliated with, endorsed by, or sponsored by the College Board, ABRSM, or any examination board or conservatoire.

Purchases

Partwise is free to download and opens three exercises, one from each of the first three units, with full marking and full explanations. Partwise Complete is a one time purchase that unlocks the other thirty nine exercises, a correct realization for every one of them, and hints. It is not a subscription and it does not renew.

All purchases are processed by Apple. Refunds are handled by Apple under the terms of the Apple Media Services agreement, not by us. Restoring a purchase on another device requires the same Apple Account.

Your Data

Partwise collects nothing. See the Privacy Policy at ofolabs.net/partwise/privacypolicy.

Intellectual Property

The app, its rule engine and solver, its interface and its artwork are the property of OFO Labs. You may not copy, decompile, reverse engineer or redistribute the app or any part of it.

Disclaimer of Warranties

The app is provided "as is" without warranty of any kind, express or implied. We do not warrant that its marking matches the convention taught by any particular teacher, course or examination board, or that the app will be uninterrupted or error free.

Limitation of Liability

To the maximum extent permitted by law, OFO Labs is not liable for any indirect, incidental or consequential damages arising from your use of the app, including any examination result or academic decision made in reliance on its marking.

Changes to These Terms

We may update these terms. Continued use after a change means you accept it. The current version always lives at this address.

Governing Law

These terms are governed by the laws of Germany.

Contact

ofolabs@gmail.com