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Privacy Policy

Effective: March 9, 2026

1. Information We Collect

We collect the following types of information when you use Crescend:

Account Information

When you sign in with Apple, we receive your Apple user identifier and, if you choose to share them, your name and email address. Apple may provide a private relay email address.

Audio Recordings

When you use the recording feature, we capture audio of your piano playing. On iOS, audio is processed on your device using on-device machine learning models. On the web, audio chunks are sent to our servers for processing and are not retained after analysis is complete.

Practice Data

We store practice session metadata, including timestamps, duration, piece information, and AI-generated observations about your playing. This data is used to track your progress and personalize feedback.

Usage Data

We collect standard usage data such as device type, operating system, app version, and interaction patterns to improve the Service.

2. How We Use Your Information

  • Provide and improve the Service, including generating personalized practice feedback
  • Process audio recordings through our machine learning models to analyze musical expression
  • Maintain your practice history and track your progress over time
  • Communicate with you about the Service, including updates and support
  • Detect and prevent fraud, abuse, or security issues

3. Audio Data Handling

Your audio recordings are handled with particular care:

  • iOS: Audio is processed entirely on your device using Core ML. Raw audio data is not sent to our servers unless you explicitly opt in to cloud features.
  • Web: Audio chunks are transmitted to our inference servers over encrypted connections (TLS). Audio data is processed in real time and is not stored after analysis.
  • We do not sell, license, or share your audio recordings with third parties.
  • We do not use your audio recordings to train our machine learning models without your explicit consent.

4. Third-Party Services

We use the following third-party services:

  • Apple: Authentication (Sign in with Apple)
  • Cloudflare: Hosting, content delivery, and data storage
  • AI Model Providers: We use third-party large language models to generate practice feedback. Practice context (not raw audio) may be shared with these providers subject to their data processing agreements.
  • Sentry: Error tracking and performance monitoring

5. Cookies and Local Storage

We use essential cookies for authentication (session tokens) and local storage for application state. We do not use advertising or tracking cookies.

6. Data Retention

We retain your account and practice data for as long as your account is active. Audio recordings are processed in real time and not retained after analysis. If you delete your account, we will delete your personal data within 30 days, except where retention is required by law.

7. Data Security

We implement industry-standard security measures to protect your data, including encryption in transit (TLS) and at rest. However, no method of transmission or storage is completely secure, and we cannot guarantee absolute security.

8. Your Rights

Depending on your jurisdiction, you may have the right to:

  • Access the personal data we hold about you
  • Request correction of inaccurate data
  • Request deletion of your data
  • Export your data in a portable format
  • Opt out of certain data processing activities

To exercise these rights, contact us at the address below.

9. Children's Privacy

The Service is not directed at children under 13. We do not knowingly collect personal information from children under 13. If you believe a child under 13 has provided us with personal information, please contact us and we will delete it.

10. Changes to This Policy

We may update this Privacy Policy from time to time. We will notify you of material changes by posting the updated policy on the Service with a new effective date. Continued use of the Service after changes constitutes acceptance of the revised policy.

11. Contact

If you have questions about this Privacy Policy or our data practices, please contact us through the Service.