Classical.com (http://www.classical.com/) Classical.com provides curated sound clips from art music repertoire that further acquaint students with the timbres of various instruments and instrumental families.   

Timbral Analysis (https://ccrma.stanford.edu/~jmccarty/formant.htm) Using acoustic analysis and linguistic knowledge, this website presents the human voice via scientific methods. This website will be of particular interest to students in the sciences who are looking to connect knowledge from music classes to their core discipline. Also, for students in the humanities this provides a more mechanical understanding of timbre that might illuminate some concepts previously glossed over.

Vocal Cords Up Close (http://www.youtube.com/watch?v=-XGds2GAvGQ) Much like the previous resource, this provides more mechanical knowledge about vocal timbre, but does so with an inside look at the vocal cords as humans sing. This is an excellent way for students to see how the voice is produced and controlled and compares in one video various vocal types and the physical equipment necessary to produce differing timbres.