The composition as a whole:
        Audio only
        Audio with Score

        Midi files are not copyrighted. Several web sites already contain midi files for a wide variety of choral compositions (e.g., Silvas Woodshed). See the Resources page for links.

        Part learning:
        Particular voice emphasized
        Particular voice omitted
        Particular voice with tempo control (only indirectly compatible with Macs)
        Online part rehearsal

        Although there is an increasing amount of Midi filies for individual part learning on the web, such files are not typically found on mega sites. You will likely need to perform a web search for them (e.g., Google). Otherwise, you may record such files yourself and upload them to your server.