Use ILLiad to get an article that UK does not own, and it's free! All you need to do is set up an account using your LinkBlue credentials, or you can ask library staff for help.
The Music Periodicals Database (formerly IIMP) provides access to more than 200 full-text titles, and citations from more than 600 international music periodicals.
Oxford Bibliographies in Music provides access to articles written and reviewed by top scholars in music. Articles contain bibliographies with links to UK Libraries' holdings.
RILM Abstracts of Music Literature is a music bibliography featuring citations, abstracts, and indexes from journals, dissertations, Festschriften, conferences, and other resources from around the world.
For dissertations written by UK graduates, check INFOKAT. Search for dissertations just as you would a book. Here's an example using "Advanced Search."
Each database is a bit different, but if you know Boolean operators and other advanced techniques, your search results will be more relevant. Here is a brief introduction to Boolean operators.
Many of the databases listed on this page have documentation, videos, and even webinars about searching. Below are some links from the companies. Also, look for "Help" icons or "Support" links when you are in a database--these are often in the toolbar at the top of the screen.
EBSCOhost (includes Music Index, RILM, & RIPM)
Oxford Bibliographies in Music
ProQuest (includes Music Periodicals Database)