The Carl Nielsen Society is based in Copenhagen, Denmark. The society’s official website is accessible in English, and on it, you can find a detailed biography, photo gallery, a complete list of compositions and recordings, performances around the world, and links to related subject of interest: Carl Nielsen Society

The Elgar Society is Britain’s largest composer society. The current society President is Julian Lloyd-Webber, cellist, and brother of Andrew Lloyd-Webber, composer of “Phantom of the Opera” and other musicals. Membership is free. Elgar Society

Another website, with links to the Elgar Society, but organized in a possibly more useful layout for American audiences is here: Elgar.org

Antonio Vivaldi is a name so well recognized that he is now the namesake of a recently launched web browser. His “Four Seasons” seems to become more popular every year. The composer’s catalog would take a lifetime of listening or performing before reaching its end. The Saint Paul (MN) Chamber Orchestra has a free listening library on its website. Compositions by “The Red Priest” can be found here: Saint Paul Chamber Orchestra Listening Library