The Nature of Western Music Theory
Terms and Conditions
Last updated: September 15, 2026
These Terms and Conditions govern your purchase and use of Temperament (the “App”), a product of Curran Crafts, operated by Matthew Curran, a sole proprietor based in New York, NY (“we,” “us,” “our”). By purchasing or using Temperament, you agree to these terms.
Temperament is an interactive music theory web application covering the Circle of Fifths, Keys & Chords, Modes, Ear Training, Jazz, Mathematics, History, and a self-assessment Quiz. It is available for free use at its public address, and also available for purchase in the license tiers described on our Pricing page.
Our order process for purchases made through checkout on this site is conducted by our online reseller, Lemon Squeezy (Sold through Link, LLC f/k/a Lemon Squeezy LLC). Lemon Squeezy is the Merchant of Record for these orders and handles payment processing, applicable sales tax and VAT, and customer service inquiries and returns related to billing. Studio, Department, and Institution licenses arranged directly with us by invoice are billed separately by Curran Crafts and are not processed through Lemon Squeezy.
Prices are listed in US dollars unless otherwise noted. We reserve the right to change our prices at any time; a price change will not affect an order already placed.
Subject to payment and these terms, we grant you a limited, non-exclusive, non-transferable license to use Temperament according to the tier you purchased:
You may not decompile, reverse-engineer, or claim authorship of the App itself. The underlying music theory content (the circle of fifths, the overtone series, standard notation, and so on) is the shared inheritance of Western music theory and belongs to no one; this license covers our specific implementation, design, and instructional material, not the theory itself.
You agree not to use Temperament for any unlawful purpose, to attempt to gain unauthorized access to our systems, or to use the App in any way that could damage, disable, or impair it for other users.
Temperament, including its design, code, instructional text, and audio, is owned by Matthew Curran / Curran Crafts and is protected by copyright. All rights not expressly granted to you are reserved.
Temperament is provided “as is” and “as available.” We make reasonable efforts to verify the musical and historical accuracy of its content, but we do not warrant that the App will be error-free, uninterrupted, or fit for any particular purpose beyond general music education.
To the fullest extent permitted by law, our total liability arising from your purchase or use of Temperament will not exceed the amount you paid for it. We are not liable for indirect, incidental, or consequential damages.
Individual licenses are perpetual for the copy purchased. Studio, Department, and Institution licenses run for the term stated in the applicable license agreement (typically one year) and do not auto-renew unless you are told otherwise at purchase. We may terminate a license if these terms are materially breached and not cured within a reasonable time after notice.
We may update these terms from time to time. Material changes will be reflected by an updated “last updated” date above. Continued use of Temperament after a change constitutes acceptance of the revised terms.
These terms are governed by the laws of the State of New York, without regard to its conflict of law principles.
Questions about these terms, or about licensing, can be sent to matthew@matthewcurran.net.