International Music Score Library Project

The International Music Score Library Project (IMSLP), also known as the Petrucci Music Library after publisher Ottaviano Petrucci, is a subscription-based project for the creation of a virtual library of public domain music scores, based on the wiki principle. Since its launch on February 16, 2006, over 300,000 scores and 35,000 recordings for over 93,000 works by over 12,000 composers have been uploaded. The project uses MediaWiki software to provide contributors with a familiar interface. Since 6 June 2010, IMSLP has also included public domain and licensed recordings in its scope, to allow for study by ear.

From December 27, 2015, the project moved to a subscription based model, where users who have not paid for a subscription are subject to a 15-second waiting period to download certain files, newly uploaded files not downloadable for the first few days, and advertising. Subscriptions cost between $1.90 and $1.14 per month, resulting in a price range of $22.80 for 1 year to $273.60 for 20 years. According to Norman Lebrecht, the change was met with a "rising surge of anger amongst composers and musicians", whereas comments to Lebrecht's article were mostly in favor of the change.