1. Who we are and what these terms cover
Clef is operated by Daniel Dratschuk, Schölerpad 235, 45355 Essen, Germany (see the legal notice). These terms govern your use of the Clef web app and your subscription. They are written for consumers; Clef is not currently offered to businesses. The contract language is English.
2. The service
Clef is a browser-based piano practice and memorization tool: it displays sheet music from a curated catalog, listens to your playing through a MIDI connection, gives per-note feedback, and schedules from-memory reviews of what you've learned.
Clef is in beta. It is actively developed: features will evolve, the catalog is curated and grows over time, and occasional rough edges are part of what the founding rate reflects. Section 12 describes how changes to the service are handled; nothing in this section limits your statutory rights regarding the conformity of digital services.
3. Your account
- You must provide accurate information and keep your credentials confidential.
- One account per person; accounts are personal and may not be shared or resold.
- Clef is not directed at children under 13, and you must be at least 13 years old to create an account.
- If you are under 18 — or under 16 in the EEA — you may only use Clef if your parent or guardian has reviewed and agreed to these terms on your behalf.
4. What you need to use Clef
Clef requires a digital piano or keyboard with USB-MIDI and a browser with Web MIDI support (currently Chrome, Edge, or Firefox), on a laptop or desktop computer. This is stated here, on the pricing page, and on the Getting Started page before you subscribe: Clef cannot hear acoustic pianos, has no mobile apps, and does not work in browsers without Web MIDI. Please check your setup during the free trial.
5. How the contract is concluded
Creating a Clef account is free and does not start either the trial or a paid subscription. If your account is eligible, selecting "Start 14-day free trial" explicitly activates the free trial inside Clef. That action requests no payment details and creates no payment obligation. When you later choose a paid plan, you are taken to a checkout page operated by Stripe, where your order and its price are summarized and you can review and correct your entries at any time before submitting. Selecting the button that starts the paid subscription submits a binding order; the paid contract is concluded when Stripe confirms it and you are returned to Clef.
We store the version of these terms you accepted together with your account, and the current terms are always available on this page. After you subscribe, we send you a confirmation email with the essential contract terms and the statutory withdrawal instruction. The contract text itself is not separately archived beyond this; keep the confirmation email for your records.
6. Trial, fees, and billing
- An eligible account may explicitly activate one 14-day free trialwith full functionality. It does not start automatically. No payment method is required; if none is on file when the trial ends, access expires and nothing is charged. You'll receive a reminder email before the trial ends. Continuing on a paid plan requires a separately disclosed paid choice and payment method.
- If you continue past the trial, the subscription renews monthly at the rate stated at signup. For the founding cohort this is $9 per month (USD); prices are final (no VAT is added, §19 UStG).
- Founding rate lock: the founding rate applies for as long as your subscription remains continuously active. If your subscription ends — by cancellation or unresolved payment failure — a later resubscription is at the then-current standard rate.
- The standard rate can change only with at least 30 days' advance notice by email, effective from your next billing period at the earliest, and you can cancel before any change takes effect. Price changes never apply retroactively and never affect an active founding-rate lock.
- Payment processing is handled by Stripe (see the privacy policy).
7. Cancellation
You can cancel at any time, effective at the end of the current billing period, through the Stripe customer portal reachable from your account — it takes two clicks. You keep access until the end of the period you paid for.
Account deletion is separate from ordinary cancellation. You can permanently delete your account from Settings → Account using the emailed same-session confirmation link. Confirmation ends access immediately, cancels the subscription, and cannot be undone; you do not keep access through the paid period. Records that Clef must preserve for tax, refunds, disputes, and teacher-referral payouts are retained separately as described in the privacy policy. Deleting an account does not remove any refund right described in the refund policy.
8. Withdrawal and refunds
EU/EEA consumers have a statutory 14-day right of withdrawal, and every customer's first paid month is covered by our 30-day money-back guarantee. Both are described in the refund policy, including the model withdrawal form.
9. Acceptable use
You agree not to:
- interfere with or disrupt the service or circumvent its access controls,
- reverse engineer, decompile, or extract the service or its content, except where statutory law expressly permits it (e.g., §69e UrhG),
- share, resell, or provide your account to others,
- use the service for anything unlawful.
We may suspend or terminate accounts that materially breach these terms, after warning where reasonable (see section 13).
10. Liability
We are liable without limitation for damage caused intentionally or by gross negligence, for injury to life, body, or health, and under the Product Liability Act (Produkthaftungsgesetz).
For slight negligence, we are liable only for breach of essential contractual obligations (obligations whose fulfillment makes the proper performance of the contract possible in the first place and on whose fulfillment you regularly rely), and in that case limited to the foreseeable damage typical for this kind of contract. Any further liability is excluded. This exclusion does not apply to liability for fraudulently concealed defects, under a guarantee we have expressly assumed, or under mandatory statutory provisions, including your rights regarding digital services (§§327 ff. BGB).
11. Intellectual property and your data
- The Clef app, its score engravings and renderings, and the site content belong to us. Your subscription grants you a personal, non-transferable right to use them within the service for the subscription's duration.
- The classical works in the catalog are in the public domain; the engraved editions Clef presents are our own work.
- Your practice data is yours. We use it to provide the service as described in the privacy policy, and you can request a copy or deletion at any time.
12. Availability and changes to the service
We aim to keep Clef available around the clock but do not guarantee uninterrupted availability; maintenance and updates may cause short interruptions. As a beta product, Clef's features will change and usually improve. If a change materially reduces functionality you reasonably relied on, you may terminate the contract early from the moment the change takes effect, and your statutory rights for digital services (§§327 ff. BGB) remain unaffected.
13. Termination by us
We may terminate your subscription with reasonable notice to the end of a billing period, and immediately for cause — such as material breach of section 8 or unresolved payment default — normally after a prior warning. Paid periods you cannot use because we terminated without cause will be refunded pro rata.
14. Governing law
These terms are governed by German law, excluding the UN Convention on Contracts for the International Sale of Goods (CISG). If you are a consumer, this choice of law does not deprive you of the protection of mandatory provisions of the law of the country where you habitually reside. There is no arbitration clause; disputes belong to the ordinary courts.
15. Changes to these terms
We may update these terms as the product evolves. For material changes, we will notify you by email at least 30 days in advance; if you do not agree, you can cancel before the change takes effect. Changes never apply retroactively, and we will not treat silence as consent to changes that alter the essential balance of the contract.
16. Severability
If a provision of these terms is or becomes invalid, the remaining provisions stay in force. The invalid provision is replaced by the statutory rules.