When writing your thesis or dissertation or composing your final project, you must get permission to use any musical excerpts in your document or compostion where necessary.
The University of Illinois provides information concerning copyright via the Thesis Office. Students may find the listed resources helpful in making and documenting their own determination of whether permission is required for the use of previously copyrighted material.
The Music & Performing Arts Library has also created a Copyright Basics guide that might be helpful.
Depending on the composer/publisher of the work you want to excerpt, you must contact the publisher or one of the copyright clearance resources below. Permission to use materials, including music, must be obtained IN ADVANCE of the intended use.
If you are writing a composition and want to "sample" another composition, you may need to acquire permission to do so. Permission to use materials, including music, must be obtained IN ADVANCE of the intended use.