The Mixolydian Mode originally ascended from G to G'. This is a common mode for traditional music.
Use this table to construct the mode starting on any note, using the pattern of intervals below.
This pattern of intervals: T-T-S-T-T-S-T* is the characteristic of the Mixolydian mode, and is a Major mode similar to the Ionian but has a flattened 7th note.
Because the mode is characterised by its interval structure, you can start on any note and progress with the same intervals to produce a Mixolydian mode in that 'key'.
This would be 'D Mixolydian':
If a piece of music seems to be in the key of D, but all C#s are played as C naturals, it's probably 'D modal' or D Mixolydian.
Examples of tunes in Mixolydian Mode are Old Joe Clarke, The High Reel, Red Haired Boy and Banish Misfortune.