Term used to describe music based on a mode. There are a number of different modal patterns which were later refined and developed into our modern major and minor scale structures. Like a scale, modes can be built on any note.
One of the most common modes is the Dorian Mode. It is formed using the intervals tone, semitone, tone, tone, tone, semitone, tone (e.g. D E F G A B C D). Following this pattern, you can begin the mode on any note. Here are the notes for the Dorian mode beginning on C:
There are seven different modes. For more information on modes and how to build them please watch the video example.
Theory behind the seven different modes.