Mixolydian/Dorian Gapped Scales and Hybrids
The Dorian scale is the same as the Mixolydian scale except that the third note is flattened by a semitone. To convert a Mixolydian to a Dorian key signature, add a flat to, or remove a sharp from, it. Likewise, to convert a Dorian to a Mixolydian key signature, remove a flat from, or add a sharp to, it. The Mixolydian and Dorian scales are thus quite similar to each other, and there are quite a few Mixolydian/Dorian gapped scales and quite a few Mixolydian/Dorian hybrids. Here are some examples.
Green Mossy Banks of the Lea, Version 2 of 2 (GB/6a/77)
Tune Analysis: D Dorian but one of the Fs is sharpened to produce a Mixolydian/Dorian hybrid. Heptatonic, Plagal.