This is something different, for those interested in learning Gregorian Chant (or, really, learning solfege). These are exercises taken from Dom Gregory Sunol's "Text Book of Gregorian Chant According to the Solesmes Method", lesson IV (intervals of a second).
I state a sequence of notes for you to sing (e.g., "do re do re do"), there is a short pause for you to vocalize your answer, and then you hear the correct notes.
Grab the mp3.
Alternative formats are available at the archive.