Frequency Analyzer
This free real-time audio analyzing program allows you to see a visual representation of what you sing, play, or speak. http://www.relisoft.com/Freeware/index.htm

Audacity
This free audio recording program allows you to record, cut and paste, slow down or speed up, change the key up or down, and many other 'studio' tasks. http://audacity.sourceforge.net/

Finale Reader
This free notation software allows you to open, view, and print sheet music documents that are created with any of the Finale family of notation software, including MusicXML files. http://www.finalemusic.com/Reader/