Captain Birdseye: you can say they are not in minor keys till you are blue in the face, but the fact is that most people's use of language uses the term "minor keys" for all these scales.You may differ, but you are in a very small minority.Most people, hearing the Mason's Apron and then the Swallow's Tail Reel, would say"aha, a change from A major to A minor". And they would be absolutely right to say so, even though the latter is in the Dorian mode, and not in your "melodic minor". The distinctive feature is the minor third.There is indeed a scale called the melodic minor, and another called the harmonic minor, as you say. There are also scales called the Aeolian minor and the Dorian minor.The melodic minor,the Aeolian minor, and the Dorian minor are all used in traditional dance music, the latter two being historically the most commonly used in the British Isles.(There are also minor scales that do not fit into these categories,Vaughan Williams' version of |Greensleeves for example, but that is a digression). The harmonic minor, as its name implies, is a selection of notes used for harmonising tunes in the melodic minor key; it is not designed for constructing melodies, though it has ben used for that.