Academic Search Premier is a large database that covers more than 8,000 journals, 85% of which are peer-reviewed and over 55% are full text, and full text for nearly 3,900 peer-reviewed titles. It covers a wide variety of disciplines.
JSTOR, a scholarly database, provides access to scholarly journal articles on the arts, sciences, social sciences, management, mathematics, and statistics, as well as images and primary sources. As JSTOR is an archival database, full-text availability of most journals starts from their first year of publication, while more recently published journal content is available after an embargo period.
ProQuest Central provides access to a vast array of scholarly journals, popular magazines and newspapers from all over the world through databases including News & Newspapers, ABI/INFORM, Ebook Central, and many more. Recommended for all subjects.
Stevens Theses and Dissertations Online contains dissertations and theses produced by students at Stevens Institute of Technology through the ProQuest database. Dissertations: 1955 - present. Master’s theses: 2017 - present.
A wide and varied wiki of music scores and MIDI recordings of music in the public domain (after the period of copyright has expired) of Canada, the US, and the EU. While the point at which works enter the public domain is different for Canada, the US and the EU, there is enough overlap that there's plenty to explore, by composer, performer, or work.
The performing-arts research library of the NYPL is located next to Lincoln Center and includes some of the best research collections available on music, dance, theater, and more.
The DPLA is a portal into the collections of libraries, museums, and archives around the country, providing direct access to the digital records of millions of items.
A commercial site that offers some value as a database of song and album information. Useful when assembling citation information (or if you'd like to know what albums can be thought of as, say, "Autumnal").
Housed at the Internet Archive, the Ethnomusicology Archive from UCLA contains more than 150,000 audio, video, print and photographic items about musical traditions around the world, going back as far as 1961.
Musical works are cited in different ways depending on their medium. Sound recordings are different from sheet music which is different from .mp3 files, so it's important to be specific when you cite a work you have used.
MLA (Purdue OWL; includes sound recordings, spoken word albums, and digital files)