Solfège is a system of assigning syllables to musical pitches. This project attempts to enable people to find songs that they just can't quite remember the words for by searching for a solfege phrase.
The solfège scale is: do, re, mi, fa, so, la, ti. In order to simplify searching, a "movable do" is used. This means that do does not always correspond to C; rather, it corresponds to the root of the key that the song is written in.