Learning tonic sol-fa has many benefits for the amateur musician but, as its main purpose is to develop inner hearing, it is difficult to master it without a teacher to pattern the intervals and provide feedback about the accuracy of the pupil's pitch. In this free software resource, grids have been designed as sol-fa modulators and staves, which the user can play with the mouse, while singing the sol-fa syllables. familiar tunes can be played 'by ear' and the sol-fa syllables ascertained or confirmed.