With Purcell and Battista, Keller was supposed to have taught keyboard at the proposed Royal Academy. He was one of the many foreign musicians who settled in England at this time, the late seventeenth century, and left only once, 1694, to travel to Holland. Keller would often perform in London on the harpsichord and though he died young contributed his "Compleat Method" for the thoroughbass. It was not published during his life but was ready. It was the first work of its kind in England since Locke's "Melothesia." Keller's "Method" included not only the instruction on thoroughbass but also instructions for tuning the harpsichord and extemporaneous bass practices over written passages. Compositions by Keller included sonatas, airs, and preludes often for wind instruments reflecting his German background and his interest in composing for the orchestra of Princess Anne of Denmark. This orchestra included the trumpeter John Shore and the players of the recorder, La Tour and Paisible. ~ Keith Johnson, Rovi