“Glorishears" is an English Morris dance tune in 2/2 time. Most print sources give it in A mixolydian. Karpeles also gives it in D mixolydian. Some sources have it with a key signature of three #'s and flatten all the G's to naturals which makes it effectively A mixolydian. I don't feel that the melody comes to a rest on the A and prefer to finish on a D which sets it in D major. You can do that or let it hang on the A.
The term "glorishears" is from the Cromwellian Protectorate; it is a condensation of "The Glorious Years." The tune was specified for several ballads, most titled "The Glorious Years of ...(regent or monarch)". It is from the village of Bampton, Oxfordshire, in the Cotswolds.
It was used by Gustav Holst for the theme of his Second Suite for Military Band in F, 1st movement where he combined it with two other folk tunes, "Swansea Town" (also the tune of "The Holy Ground" in the Chanties & Sea Songs section) and "Claudy Banks" and made it into a march.
It was printed Karpeles & Schofield's A Selection of 100 English Folk Dance Airs (1951), Bacon's The Morris Ring (1974), Raven's English Country Dance Tunes (1984), and Mallinson's Mally's Cotswold Morris Book (1988).