GNU Solfege
Ear training software
GNU Solfege is an ear training program for X Windows written in Python, using the GTK+ 3.0 libraries. You can practice harmonic and melodic intervals, chords, scales and rhythms, and you can add new exercises using a simple plain text file format.
Ear training is a big subject with many connections to music theory and performance of music.
To use this software, you need some basic knowledge about music theory.