Archive · Library · Collections of the Gesellschaft der Musikfreunde in Vienna are the most important private music collections worldwide. Even if one includes publicly owned collections, they remain among the five most important collections in the world, with only the state-owned library collections in Berlin, London, Vienna and Washington being of comparable significance. What sets the collection of the Musikverein apart is not only the wealth of outstanding individual artefacts but also their contextual significance. It was a founding ambition of the Gesellschaft der Musikfreunde to document the history of music as comprehensively as possible. Music autographs, manuscripts and printed scores, letters, books and periodicals, paintings, sculptural objects and photographs, files and documents of all kinds, mementoes, recordings and musical instruments have all been added to the collection.It proved very fortunate that this passion for collecting began as early as 1812. The Musikfreunde acted promptly to claim priceless compositions as these were released when former court orchestras were disbanded. They were successful in bidding during the auction of Beethoven’s estate in 1827. Only a little later, the music library of Beethoven’s patron Archduke Rudolph was bequeathed to the Gesellschaft: ninety boxes each weighing 250 kilogrammes and containing priceless Beethoven documents. Another gift in 1870 brought what is perhaps the most famous of all Beethoven’s manuscripts to the collection: the transcription of the “Eroica” score, with its dedication to Napoleon erased by the composer.Further to these, original manuscripts from Wolfgang Amadeus Mozart and Joseph Haydn are among the highlights of the collection. In the case of Franz Schubert, the Gesellschaft possesses the autograph scores of all the symphonies (with the exception of the Fifth), among other items. Johannes Brahms left his estate in terms of scores and books to the archives of the Musikverein, as did Gottfried von Einem at a later date. The list of famous names can be extended almost at will: The archives contains precious documents pertaining to Bruckner and Mahler, Schumann and Mendelssohn Bartholdy, Johann Strauß and Joseph Lanner, Hugo Wolf and Richard Strauss, Anton Webern and Alban Berg. The Musikverein conserves these treasures using state-of-the-art technology and security. Exhibitions are regularly held in the exhibition space of the Musikverein and provide a glimpse into the Archives · Library · Collections. A fixed point in the events calendar is the annual concert series “Nun klingen sie wieder” (“They sound again”), in which performances showcase the historical instruments from the collections. Archive · Library · Collections are a Centre of Research. The quality of the collected objects and the expertise of the team at work here ensure the archive is a much sought-after partner for international exhibitions and research projects. The items in the collections are accessible to researchers. From October to June, the Reading Room (“Lesesaal”) is open to the public for study purposes on Mondays, Wednesdays and Fridays until midday.