International Music Score Library Project
The International Music Score Library Project (IMSLP), also known as the Petrucci Music Library, is a digital library offering free access to public domain music scores and select works under specific licensing permissions, adhering to Canadian copyright standards.[1] Founded in 2006 by Edward Guo, a composition student at the New England Conservatory of Music, the project aims to create a comprehensive virtual archive of musical works whose copyrights have expired or been waived.[2][1] By October 2025, IMSLP hosts over 247,000 works encompassing more than 800,000 individual scores and parts from approximately 27,000 composers, alongside recordings and performer data, making it one of the largest repositories of freely available sheet music.[3][1] Owned and operated by Project Petrucci LLC, the site relies on volunteer contributions for uploads and maintenance while enforcing guidelines to avoid unauthorized copyrighted material.[1] The initiative has faced significant challenges, including a 2007-2008 shutdown due to complaints from the National Music Publishers' Association over potentially infringing uploads and subsequent 2011 disputes with the Music Publishers Association of the UK, which prompted temporary takedowns but ultimately reinforced stricter review processes.[4][5]
History
Founding and Initial Launch
The International Music Score Library Project (IMSLP), also known as the Petrucci Music Library, was founded on February 16, 2006, by Edward W. Guo, an 18-year-old Canadian composition student and sophomore at the New England Conservatory of Music.[6][7][8] Guo, operating under the username Feldmahler, established the platform as a non-commercial, wiki-based digital repository specifically for public domain music scores and parts, addressing the challenge of accessing out-of-print historical editions that were otherwise scarce or expensive.[1][2] The project's name drew inspiration from Ottaviano Petrucci, the 16th-century Venetian printer who produced the first substantial collection of polyphonic music using movable type in 1501, symbolizing IMSLP's aim to democratize access to musical notation in the digital age.[1] Launched with wiki software to enable collaborative contributions, the initial site hosted a modest collection of scanned historical scores, primarily from the public domain, uploaded by Guo and early users seeking to preserve and share freely available materials without commercial intent.[9][10] From its inception, IMSLP operated under a volunteer-driven model, with Guo serving as the lead programmer and administrator, emphasizing open access while adhering to copyright guidelines for public domain works—typically those published before 1928 in most jurisdictions at the time.[7] The platform's early technical setup relied on basic web hosting, quickly attracting musicians, scholars, and enthusiasts who recognized its utility for research and performance preparation.[2]Early Growth and Community Building
The International Music Score Library Project (IMSLP), founded by Edward Guo—a composition student at the New England Conservatory—began operations on February 16, 2006, initially as a volunteer-driven repository for public domain musical scores.[2][6] Guo, operating under the banner of Project Petrucci LLC, hosted the site on servers in Canada to leverage more permissive public domain rules compared to stricter U.S. copyright interpretations, enabling uploads of scores entering the public domain after 1923 in Canada but not yet in the U.S.[2] This jurisdictional strategy, combined with free access to digitized editions often scarce in physical libraries, spurred initial interest among musicians and scholars seeking historical materials. Early expansion accelerated in 2007, with the library surpassing 5,000 files by April 10—less than two months after a prior milestone—reflecting contributions from a burgeoning network of users who scanned and uploaded out-of-print scores from personal holdings, antiquarian books, or institutional scans.[11] Growth stemmed from Guo's open invitation for global participation, positioning IMSLP as a collaborative alternative to commercial score vendors and proprietary digital archives, which often charged high fees or restricted access to pre-1923 works.[2] By mid-2007, the site's appeal had drawn contributors from diverse regions, including Europe and North America, fostering a sense of communal stewardship over musical heritage amid frustrations with escalating reprint costs for rare editions. Community building emphasized user guidelines for verifying public domain status and formatting uploads, which helped maintain quality despite the absence of formal peer review; forums and direct communication with Guo encouraged discussions on copyright ambiguities, particularly for European works under varying national terms.[11] This volunteer ethos, akin to open-source software projects, rapidly built a user base of performers, educators, and hobbyists who valued the site's non-commercial model, though it also invited scrutiny from publishers wary of potential overreach into gray-area copyrights.[2] The influx of submissions not only diversified the catalog—spanning Baroque to Romantic eras—but also highlighted IMSLP's role in democratizing access to primary sources, predating widespread digitization by major institutions.2007 Shutdown and Immediate Aftermath
On October 19, 2007, the International Music Score Library Project (IMSLP) shut down its website after administrator Edward Guo, known online as Feldmahler, received a second cease-and-desist letter from Universal Edition, an Austrian music publisher, dated October 13, 2007.[12] The demands centered on works IMSLP hosted that were public domain in Canada—where the project was based and servers were located, under a life-plus-50-years copyright term—but remained copyrighted in the European Union under a life-plus-70-years rule, including editions of composers like Mahler, Berg, and Webern published by Universal Edition.[13] Guo, a college student lacking legal or financial resources to contest the claims or implement geoblocking for international users, opted to close the repository to mitigate liability risks.[12] In an open letter posted on the site, Guo reaffirmed IMSLP's mission to democratize access to public domain musical scores as a core human right tied to cultural heritage, while expressing regret over the closure and pride in the community's contributions, which had amassed thousands of files since the project's 2006 launch.[12] The project's forums at imslpforums.org stayed online for ongoing discussions, and Guo invited inquiries via email for potential domain transfer or support.[12] The immediate aftermath saw widespread user dismay across music communities, with forum threads decrying the shutdown as an overreach stifling free access to heritage materials and highlighting tensions between national copyright regimes.[14] Some contributors archived downloaded scores privately or shared mirrors informally to preserve availability, while Universal Edition posted a forum clarification asserting their entitlement to enforce copyrights globally against unauthorized distributions.[15] These reactions underscored broader debates on reconciling public domain variances without extraterritorial legal battles, prompting Guo to begin revising upload policies in offline consultations with volunteers.[12]Reopening and Structural Reforms
Following its closure on October 19, 2007, triggered by a cease-and-desist demand from Universal Edition regarding potentially copyrighted scores, the International Music Score Library Project (IMSLP) underwent a comprehensive review of its over 16,000 hosted files to verify public domain status and compliance.[16] This process, completed by June 2008, enabled the site's reopening on June 30, 2008, with a reaffirmed focus on providing free access to public domain musical works while addressing publisher concerns.[16] Key structural reforms included relocating operations to align with Canadian copyright jurisdiction, where public domain status for anonymous or pseudonymous works follows a life-plus-50-years term—shorter than the life-plus-70-years standard in the United States and many European countries—thus expanding the eligible collection without violating host-country laws.[3][17] To handle contemporary works, IMSLP launched the International Music Database Project (IMDBP) as an affiliated initiative, designed to collaborate with music publishers for distributing modern scores under Creative Commons licenses, separate from the core public domain repository.[16][18] Submission processes saw minimal alterations, requiring only an additional link to IMDBP for applicable files, preserving user accessibility.[16] The reopening also featured rebranding to incorporate "Petrucci Music Library," honoring early music printer Ottaviano Petrucci, and a commitment to backups for data preservation alongside donation appeals for sustainability.[16] These changes prioritized empirical verification of file eligibility over expansive interpretations of international copyright, reducing legal vulnerabilities while maintaining the project's mission against retroactive extensions of protection terms that encroach on established public domain materials.[16][17]Expansion and Milestones Post-2008
Following the reopening on July 1, 2008, IMSLP underwent rapid expansion, with its collection surpassing 10,000 work pages by June 21, 2008, shortly before full public access resumed.[19] Content growth accelerated in subsequent years, driven by volunteer uploads and stricter copyright policies that mitigated legal risks. By September 9, 2009, the library had amassed 36,000 scores, reflecting a surge from pre-shutdown levels.[19] This momentum continued, reaching 40,000 scores by October 24, 2009, accompanied by over 100,000 daily downloads for the first time on October 25.[19] By February 2011, holdings exceeded 85,000 scores, representing parts for nearly 35,000 works, with thousands added monthly.[4] Key recognition came on July 28, 2009, when IMSLP was named one of PC Magazine's top 100 websites of the year, highlighting its value as a free resource for public domain scores.[19] Partnerships enhanced functionality and reach; on July 23, 2009, a new publishing collaboration was announced to facilitate legal content additions.[19] In February 2012, integration with Peachnote.com introduced a PDF viewer and public annotator, enabling users to annotate scores collaboratively.[19] Mobile accessibility expanded via July 2012 integration with the piaScore iPad app, allowing direct downloads.[19] To address jurisdictional copyright variances, Petrucci Music Library - Canada launched on July 1, 2013, providing a compliant subdomain for Canadian users.[19] Collection size continued scaling, exceeding 329,000 scores from over 13,225 composers by October 2015.[20] By around 2017, it held over 390,000 scores encompassing approximately 119,000 works by more than 15,000 composers. Milestones extended to audio content, with recordings reaching 90,000 by June 19, 2025, underscoring sustained growth in multimedia offerings.[19] This trajectory was supported by community-driven uploads and technical upgrades, such as MediaWiki enhancements in 2009, fostering broader user engagement without compromising public domain focus.[21]Recent Developments and Growth Metrics
As of August 19, 2025, IMSLP hosted 820,000 scores across its Petrucci Music Library.[18] By September 8, 2025, the platform's collection of recordings had reached 91,000.[18] These figures reflect ongoing contributions from volunteer uploaders and work tags, with the number of distinct works featuring scores or parts increasing to 247,000 as of August 26, 2025.[18] Earlier in 2025, milestones included 795,000 scores on February 19, 242,000 tagged works on March 4, and 89,000 recordings on March 17, demonstrating consistent quarterly expansion driven by public domain additions and community verification processes.[18] In late 2024, the score count stood at 785,000 by December 5, underscoring a pattern of incremental growth tied to annual public domain entries and digitization efforts.[18]| Date | Milestone |
|---|---|
| January 3, 2025 | 240,000 works with scores or parts[18] |
| January 5, 2025 | 88,000 recordings[18] |
| February 19, 2025 | 795,000 scores[18] |
| March 4, 2025 | 242,000 works with scores or parts[18] |
| March 17, 2025 | 89,000 recordings[18] |
| August 19, 2025 | 820,000 scores[18] |
| August 26, 2025 | 247,000 works with scores or parts[18] |
| September 8, 2025 | 91,000 recordings[18] |